Years later, but for anyone who is struggling with this there is a really easy way to do this if the resulting automator app can have the .command file location hard coded:

Add the Get Specified Finder Items action and choose your .command file.

Add the Open Finder Items action.

And now you are done.

Save the app and execute it from anywhere.

I know this is obviously a no code solution but why not 😅

Have a grat day.