Replace the Nth occurence of a text

The goal I have is simple, but I can't figure how to do it in C2, I am sure it is easy though..

I know the replace(src, find, rep) does exists, but it replace every ocurence of find with rep. Or I would like to be able to check how many time find is present, and to replace only one chosen of the occurence of find with rep

exemple:

"01101112"

I want to remplace the second 1 with A, and only this one:

"01A01112"

Is there an easy way to do this?