You can always add a shell alias to the s:Shell-Startup script that will call your editor from its real path using whatever alias you choose.
So, using the VIM: assign mentioned by squidbass for example:
Alias vi vim:vim
Or by using its full path, say it's "Work:Productivity/Vim/vim"
Alias vi "Work:Productivity/vim/vim"
Now, to edit that text file, you would simply type "vi workbench:misc/text.txt" in your shell.
Yeah I always use shell aliases... just like UNIX hehe (don't tell anyone that though)

I used to have one setup for Python too, so I can just launch Python scripts easily. Maybe I had that or the Python dir was part of where AOS looks for programs... it's PATH, can't remember how to set that though...
EDIT: I think it's something like:
path add vim:vim