1. The TM ART 4.2 Monitor Workbench User Guide is here:
Starting on page 121 is a section called
Testing Specific Application Types
It can help you decide which application type to choose.
Also in the TM ART Monitor Workbench online help there is a topic called
Available Application Types
2. But you asked about appref-ms files. I Googled a bit and found these web sites:
So appref-ms files are links or pointers and not the actual application itself. One possibility might be to find the associated .exe (maybe you could run task manager while double clicking the appref-ms file?) and decide what application type to use.
I did search into the BMC knowledge base and I cannot find that anyone has asked about appref-ms files before.