Donnie will lead his men against Brian O'Driscoll's Leinster knowing that at least two wins from the last three games are necessary to keep Glasgow in the Heineken Cup.
"We have a big challenge, but we still have a chance," he said in The Scotsman, stepping into the boots of Jon Petrie, who is being rested. "Our aim has always been to qualify for the European Cup again and that is still on for us.
"I'm really looking forward to leading the team out. I've been here a long time and never been captain, so it is a massive honour and very exciting for me. JP has been a fantastic leader and I've had chats with him about how he thinks I should play it.
"But I remember Jason White saying before the Six Nations that he wanted to just go out and lead by example and that's pretty good advice I think. Sean [Lineen] has said to me to just go out and be myself, and hopefully the guys will follow my lead. I am reasonably vocal and I make an effort to give vocal support when I play, because I know players like encouragement.
"Obviously, it's difficult right now [since the SRU announcement of cuts] and guys are worried about their futures, but all we can control is the rugby and we have to focus on that.
"I have to be honest and say that after four games I'm not yet back at the level I was playing for Scotland in 2004, but that has always been my goal and being selected for the training camp is a real positive for me. I don't know whether it means I have a chance of touring South Africa with the senior squad or Canada with the A team; all I can do is go out and do my best for Glasgow."
New head coach, Sean Lineen, continues to try different combinations of players with one eye on next season. Sean has signed two new wingers and admitted yesterday he has four more players in his sights, and plans another five signings before "this becomes my team."
Donnie added: "Sean has come in and done good things and there is an excitement about the future despite the present uncertainty. What I'm excited about this week is the young guys coming in - Fergus Thomson, James Eddie, Ben Prescott, Colin Gregor and Stuart Corsar, who is on the bench."