Win Remote Desktop(V2.1.0) can connect to Windows from Mac when using VPN'ed on Windows

on Win Remote Desktop(V2.1.0) I can connect to Windows using IP address (assigned by home wireless router/modem).. When I VPN from Windows to office network(requires smart card authentication as well) after this I can't remote in from Mac to Win. cant even ping the windows IP machine from my mac now. Any help appreciated...Windows not much use without the VPN connection AND not possible to VPN from Mac which is a home machine

tried to establish the VPN session from my remote desktop on mac..smartcard seems to know this request is from another computer