A family of Microsoft word processing software products for creating web, email, and print documents.
If you want to use all of the found string, one set of parenthesis is all that you need.
(^13[A-Z ]{1,}^13)
and then
\1
in the Replace with box.
Actually, if you want to use all of the found string, no parentheses are needed!
Find = ^13[A-Z ]{1,}^13
Replace = ^&