Hello guys!

I don't know if my title is clear but let me introduce my problem:

I'd like to know how to do this :

"performance1" (with the 1 at the top of the word)

At the end of the same sheet :
1: the performance is calculated from the ratio between...

I think it's not difficult it's like a hypertext link but I don't know the step to do this..

Thanks if you can help me