I need a code that will edit a random number

I need a code that will do this:

If Part# = "124711060301" then Part# = "12471.10.603.01" but for various numbers. The pattern will remain the same - 5digits.2digits.3digits.2digits.

I am clearly NOT a programmer but am having to edit EDI maps so expect to see me here again. lol

Thanks in advance!

Connie