Ray,
If you are talking about the Cisco VPN client, the not really. if they have install the client - and have the information from the .pcf file - this can be used anywhere.
However - if you go down the WebVPN, Cisco Secure Desktop:-
1) Registry check - exists, does not exist, DWORD, String
2) File check - exists, does not exist, version, checksum
3) Certificate check - all the information
4) Windows version check - Win 2k/XP/Vista/9x
5) IP address check - range & mask
HTH.