Team Explorer Visual Studio 2013: External Tools arguments are empty

Hi,

We're using Microsoft Team Explorer for Visual Studio 2013, update 3 has been applied

I'd like to add external commands to the tools menu; every time the external arguments are empty

Simple example is to add "open file location" command:

Command: explorer.exe
Arguments: $(ItemPath)

Every possible argument choice passes empty strings to the external command.  I could not get this to work in Team Explorer VS 2012 or Team Explorer VS 2013 Update 3.

Any suggestions?

Thanks