Ronaldo scored in that match to cancel out Danny Welbeck's opener, but did not celebrate against his former club.
The Portuguese forward has now insisted that he would celebrate if he scored in Manchester but does not have anything planned at this stage.
He told The Sun: "I can't say how I'd celebrate, it would be something spontaneous, but I'd love to be in that situation.
"I'm sure they will receive me well. After the years I spent there and the friendships I have, I'm sure it's one of the places where they'll applaud me most. It was a beautiful time."
Madrid must score in the second leg tomorrow night to have any chance of reaching the last eight.