ANYONE who imagined that the Paul Lambert who joined Celtic yesterday is the same man as left Motherwell 17 months ago would only needed to have listened to his ambitions now that he is back in Scotland.

''I didn't come here just to win things domestically,'' he said. ''I won a Champions' Cup medal with Borussia Dortmund and now I want to do the same with Celtic.''

The chances of him harbouring hopes along those lines in his Fir Park days would have been rather slim, without being disrespectful to Motherwell, but it is not just in career targets that Lambert, who cost Celtic close to #2m, has a different perspective. He indicated yesterday after completing the deal that will see him make his debut in the derby game today that he is a changed player from those formative years at St Mirren and Motherwell.

''I used to chase after everything then,'' he said, '' but now I leave that to the guys who have that job.

''I learned so much in Germany from so many great players that I hope I can bring some of that European experience to help Celtic get among the best in Europe again. This is not a move down for me, because Celtic are a very big club with a huge support that would be hard to rival anywhere in the world.''

Lambert, whose wife's homesickness was the main reason he returned to this country, seemed still a little emotional about the farewell ovations he received after his final game for Borussia, in the 2-0 win over Parma, on Wednesday night.

''That will live with me for the rest of my life,'' he said, ''It was greater even than the European Cup final.

''Everybody there, the fans, the management, and the players were so good to me.''

Lambert has known for weeks that he would be joining Celtic, but the date was the one matter to be resolved. He didn't find it a problem playing while knowing that he would be moving on. ''I was never going to let myself or Dortmund down because the people there meant so much to me.''

Lambert has no doubts that Celtic are a club on the way up the ladder.

''The performances of the players this season, and the massive support they have been getting, show they are on the way forward,'' he said. ''I want to see them taking a step up into the Champions' League and doing well. I know what it is like to win the tournament and I would like to do it again here.''

Even so, it is occasionally difficult for Lambert to believe what has happened to him in the last year-and-a-half. ''If I sit down and think about it, leaving Motherwell then winning the highest honour in club football, I have to say it is just crazy. But that is football. It can lift you up or kick you in the teeth. You just never know. I am very proud to have done what I have done and I would love to think I can do the exact same here.

''I have a great opportunity with Celtic and it is funny that Dortmund have a great rapport with this club.

''There were Celtic jerseys in the crowd on Wednesday, and the crowd chanted 'Celtic, Celtic.' Hopefully, my coming here will bind them even closer.''

Lambert made the point that the most important lesson he has learned is that games are won or lost on a team basis. ''You win together and you lose together. It is not about one man or another man. I learned so much from players there who are good friends, like Andy Moeller, Jurgen Kohler, and Paolo Sousa. My game came on leaps and bounds with their help and I hope I can pass on what I have gathered to the younger players here.''

In the context of the players with whom he has become familiar, the prospect of Paul Gascoigne today, naturally, would not seem as daunting as a few months ago. ''To be honest, it doesn't matter to me who I play against or even which team. It would be a massive game for me tomorrow whether it was Rangers or my old club, Motherwell, we were playing. It is my job to do my best.''

He acknowledged that Borussia tried to change his mind at the last minute on Wednesday, but his mind was made up. ''I was looking forward to joining Celtic. They have a great tradition and what we need to do is to get the team up among the best in Europe again. I know already that their fans are unbelievable.''

He likes the role that he was given with Dortmund and it is almost certain Wim Jansen will utilise his talents in a similar way. ''Paul is a good passer, and can play well defensively. That is why I have wanted him since soon after I came to Celtic. I know what he can bring to our team, but I also know he is able to change if he has to play a little differently for us than he did at Dortmund.''

While Jansen has studied the new man's style when playing for Scotland, as well as on video, he had not spoken to him until training yesterday. However, the Dutchman believes the research he has done and the information gathered from elsewhere has told him enough to warrant adding Lambert's name to the growing list of newcomers inside the dressing room.