"which" in PowerShell invokes TCC?

This is in PowerShell: TCC is invoked (and doesn't exit). COMSPEC is set to CMD.EXE. What's going on?
Windows PowerShell
Copyright (C) 2009 Microsoft Corporation. All rights reserved.

C:\Users\vefatica> which touch

TCC  14.03.59   Windows 7 [Version 6.1.7601]
Copyright 2013 JP Software Inc.  All Rights Reserved
Registered to Vincent Fatica - 5 System License

touch is an internal command

Well, I figured that out! I don't even remember this:
v:\> dir /km u:\which.btm
1997-10-22  09:47          2,791  which.btm
I didn't write it. It looks like it might have come from JPSoft.
An old Mike Bessy one...
You seem to have associated a persistent instance of TCC with the .BTM extension. Might be better to add /c to the association so it would not be persistent...