Colin told the Evening Times: "Beating Connacht at Firhill in our final home game of the season and final game at the ground to claim the play-off berth was massive.
"It was pretty emotional for all the boys who will be moving on in the summer, but the job is only half done.
"I am gutted to be leaving at the end of the season but I want two more games in a Glasgow shirt before it is finally over.
"We will go to the RDS believing in our ability to beat Leinster on their patch as we did in the Pro12 in the first half of the season.
"No-one is underestimating how tough that will be, but there is no bigger confidence boost than to get our first win over Connacht in three years to put us in the play-offs.
"I will never forget Saturday night. It was just a great way to say goodbye to the home support who have been fantastic for us over the campaign."