Team Coding with TFS 2015 using the External (Command Line) client

We are attempting to configure Team Coding to utilize the command line interface of TFS 2015 in order to take advantage of all the features of TFS, specifically for the use of check-in policies beyond a simple check-in comment. Check-out and Undo Check-out requests work as expected but all check-in requests fail. Examing the VCS Command Log and the command line request it looks like the command is malformed with regards to the source for check-in. The VCS command is similar to the following:

“C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\TF.exe” checkin /comment:“Check-in #1” $/ProjectABC/SectionA/Group1/H:\WorkSpaceRoot\ProjectABC\SectionA\Group1\SchemaSpec.Sample_PKG.PKB

The source specification of the command line is concatenating the VCS location together with the mapped workspace file specification on the local computer (H-drive path). TFS responds with the following error:

TF10123: The path $/ProjectABC/SectionA/Group1/H:\WorkSpaceRoot\ProjectABC\SectionA\Group1\SchemaSpec.Sample_PKG.PKB’ contains the character ‘:’. Remove the ‘:’ and try again.

Clearly, TFS identifies the ‘:’ of ‘H:’ as incorrect. Is this due to a Toad configuration issue or is it a problem with Toad’s use of the command-line client?