Because your acronyms are not enclosed in parentheses, you need to delete the following two lines from the code:
.Start = .Start + 1
.End = .End - 1

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Hello,

I had already removed the 2 lines
.Start = .Start + 1
.End = .End - 1
as i statued they were the 1st and last characters of the acronym so respectively "(" and ")".

Unfortunately i still have a error "5560" and the ".Execute" is highlighted (yellow).

When i use "[A-Z]{2}" instead of "[A-Z]{2,}" every word with 2 upper letter are selected.
Once i put the "," in the expression, i have the '5560' error.

Thank you,