how to know the changeset used in my local folder

My local machines has folders mapped to different changesets from TFS.

With powershell, I've been able to get the latest changeset from TFS, but that is NOT what I want. I want to get the current changeset used in each folder.

So, I came across this nice command:

tf history . /r /noprompt /stopafter:1 /version:W

I am looking for a way to call that command from powershell. When I try, I get the message:

The term 'tf' is not recognized as the name of a cmdlet, function, script file or operable program.

Any ideas?

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