I'm going to play with changing the behavior based on whether or not the program is a bundle.
If you use the browse command to an App you can get the bundle path otherwise typing in a command on the program line will allow posix style command execution.
Ok so here is what will be in the next build.
The arguments for Mac (and linux) should be separated thusly
"arg1" "arg2" "arg3" and so forth. Expressions would be like this "[Filename]" as an arg.
If MacOS finds an bundled app in the path which would be the case if you used browse, it will pass the command and args to the App via the MacOS API.
If the path for the executable is not an app (you typed it in), we'll use the vfork call.
So for example, if I try a command of
/bin/ls
and args of
"-l" "[Filename]"
I see an extended listing of the file on standard output.
You are welcome to play around with this using shell, terminal, whatever and it should work as long as you get the args right.