HELP! A shortcut that open other shorcuts!
I looked at the site for the app you mentioned, External Keyboard Helper Pro, which has some tutorials. This section may help:
EKH Tutorial 5 - Application shortcuts and Text strings 

A nice feature in External Keyboard Helper is the possibility to add
Application shortcuts and Text strings to keys. In this example I will
configure Alt+G to start Gmail and Alt+M to start Maps. I will also
make it possible to quickly write http://www.apedroid.com by just
pressing Alt+A.
First I enter the Advanced settings and choose to setup some
Application shortcuts.

Perhaps that setting has what you need?