Create PatchInstaller NSH-Script from Template

we have introduced a patch installer for our software. Therefore we are using CMake with NSIS with WPatch Plugin to identify modified files between two releases and generate a WGenPatDir.nsh file. Our goal is to modify the Patch function like this:

Function Patch

        

        StrCmp $3 "CHECK" after_save

                IfFileExists '$INSTDIR\$0' 0 after_save

                        DetailPrint "Rename orignal file $INSTDIR\$0 to $INSTDIR\$0.orig"

                        Rename '$INSTDIR\$0' '$INSTDIR\$0.orig'

after_save:

        DetailPrint 'Patch: $0'

        StrCpy $0 '$INSTDIR\$0'

retry:

        WPatch::PatchFile /NOUNLOAD     ; expects $0:file path, $1😳ptions, $2😛atch path

        IntCmp $1 0 continue can_skip 0

                SetErrors

can_skip:

                SetDetailsPrint listonly

                DetailPrint '=> Error $1'

                SetDetailsPrint both

                IntCmp $1 1 0 continue continue

                        MessageBox MB_RETRYCANCEL|MB_ICONEXCLAMATION $(^FileError_NoIgnore) /SD IDCANCEL IDRETRY retry

                        Abort

continue:

FunctionEnd 

 

This function ensure, that original files will be renamed to new ending “.orig”.

Is there a possibility to adapt the generated WGenPatDir-File? Maybe a template file, which is used during generation process.