How to use regex capture groups/backreferences in Search & Replace?

[nevillepark]

Hi, a big reason I use Markor is its search and replace function. I have successfully used regex capture groups in search, but is there a way to use backreferences when replacing text? I've tried $1 and \1 but both just insert that verbatim rather than using the capture group.

E. g. if I want to replace all instances of "AM" and "PM" with "A. M." and "P. M.", (A|P)M will find both "AM" and "PM". If I put \1. M. in the Replace field, though, I don't get "A. M." and "P. M.", I get \1. M. Likewise with $1. M..

Am I using the wrong character? Is there a proper way to use backreferences when replacing text? Or is this not a feature?