The special characters ^c and ^s are supported only in non-regular expression and in UltraEdit regular expression finds/replaces whereby the clipboard content or the selected text is interpreted as UltraEdit regular expression string on using ^c and ^s in an UltraEdit regular expression find/replace. ^c and ^s are not available for Unix and Perl regular expression finds/replaces because of ^ as special meanings in Unix/Perl syntax.

There could be used the following macro using the UltraEdit regular expression engine:
For the posted example text can be used also the following macro using a single Perl regular expression replace all executed from top of the file:

You are right, ^c and ^s could be used also in Unix and Perl regular expression replace strings as I could find out now. I was not aware of that fact at all until now although using UltraEdit already since 20 years. I could verify that with UltraEdit v10.10c released February 2004 and some other versions up to UltraEdit for Windows v28.20.0.92 released November 2021. UEStudio supports from first released version up to version 21.10.0.32 also ^c and ^s in replace string of a Unix or Perl regular expression replace.

No version of UltraEdit or UEStudio supported according to my tests ^c and ^s in search string of a Unix or Perl regular expression find/replace. In the Unix/Perl regular expression search string ^ is always interpreted as beginning of line and ^c and ^s results therefore in searching case-sensitive or case-insensitive depending on option Match case for the character c respectively s at beginning of a line.

The special characters ^c and ^s can be used in non-regular expression and UltraEdit regular expression finds/replace in search and in replace string.

The usage of ^c and ^s does not work anymore since UEStudio/UltraEdit for Windows v2022.0.0.70 up to currently latest v2022.1.0.112.

There is not described detailed enough in help of UltraEdit/UEStudio where exactly ^c and ^s can be used in regular expression finds/replace with the three available regular expression engines. I found nowhere in file changes.txt in program files directory of UltraEdit, in changes_ues.txt in program files directory UEStudio, in all UE/UES hotfix information ever published public and archived by me and in all information sent to beta testers by email in the past and also archived by me an information about usage of ^c and ^s in Unix/Perl regular expression replace strings. So, I don't know if that is a promised feature of UE/UES or worked just by chance in all versions of UE/UES < 2022.0.0.70. Well, there were a few versions in my tests on which ^c and ^s worked only in replace string of a Unix regular expression replace, not in a Perl regular expression replace string.

You have to contact UltraEdit support by email and ask for clarification regarding to the support of ^c and ^s in Unix/Perl regular expression strings. I don't know if the behavior of UE/UES v2022.0.0.70 to v2022.1.0.112 regarding to ^c and ^s in Unix/Perl regular expression replace string must be rated as bug as that should work or the change was done intentionally because of ^c and ^s in Unix/Perl regular expression replace strings worked just by chance and not by design in UE/UES prior v2022.0.0.70.