Midfielder Lee McCulloch is relishing his involvement in the European campaign, having joined from Wigan in the summer.
He added on ITV1: "I had a shot from long range that I should have hit the target with, I took my eye off the ball a bit.
"I think it breeds confidence when you're pulling off results like that."
Barcelona missed occasional chances, notably when Thierry Henry, who was later substituted, headed over the bar from close range midway the second half.
"They never really created that much," said McGregor.
Reflecting on his outfield team-mates' display, he said: "I thought the boys worked very hard and they deserved a draw in the end."
McGregor admitted he flicked a free-kick from Ronaldinho onto the bar in the first half.
The ball went behind for what should have been a corner but Rangers escaped with a goal kick as the officials failed to notice McGregor's decisive intervention.
"I got a wee touch," McGregor admitted, "but I'm not going to turn around (to the referee) and say, 'By the way I got a touch'."