I'm trying to write a validation rule for phone numbers with extensions. I want to be sure there are exactly 10 integers to the left of the letter "x". It needs to ignore special characters and only count integers.
I can't find a useable REGEX formula for this. I can use the FIND function to find the "x" but I'm not sure how to count the number of integers to the left of it.
This is the format numbers will be in: (999) 999-9999 x123. Right now, the system allows something like this (999) 999-99999999 x123.