How to replace any 7 digit number at a random position in a cell

Hey there,


I tried to solve my problem by going through an endless number of existing threads but unfortunately nothing I found was quite what I was looking for.


THE PROBLEM:
I have a table with cells that contain mostly text in varying length. Somewhere in those cells, every now and then, in the middle of all the text there is one or more 7 digit numbers. I need to replace these numbers with XXXXXXX. Sounds simple, right? But I have no idea how...


I am sure it is somehow possible with the right combination of IF, MID, LEFT, LOOKUP etc but I just couldn't it figure out.


HELP!