I assume you're referring to the users ROAMING profile path as opposed to their local profile path.

Use something like this...

$objUser = GetObject("WinNT://MyDomain/BJones,user")
? $objUser.Profile

If all you need is the profile path, this method is fine. If you plan to read/manipulate various Active Directory attributes, you'll want to use "LDAP://" calls rather than the WinNT:// calls.