Approach 1 with helper script
"R:\REPOSITORY\FILES\Dropbox\linux\shared\home\XXXX\scripts\cygterm-launcher.bat" "$(FULL_CURRENT_PATH)"
helper script
for /f %%i in ('C:\cygwin\bin\cygpath %1') do set UnixPath=%%i start "" "S:\Program Files\KiTTY\kitty_portable.exe" -cygterm -cmd "bash %UnixPath%" -
Approach 2 without helper script
c:\cygwin\bin\bash -c "_script=$(/usr/bin/cygpath '$(FULL_CURRENT_PATH)'); /cygdrive/s/Program\ Files/KiTTY/kitty_portable.exe -cygterm -cmd \"bash '$_script'\" -"