How to control remote VnC servers over VPN?

[Gamlem, Noralf]

First: Please bear with me if this subject has been discussed earlier,
but there's so much VPN-stuff in the previous postings that I'm unable
to search it properly...

I'm trying to access a remote VPN-server which connect to the corporate
LAN over VPN, but fail. The other way around it's no problem (using a
remote vncviewer to access a computer in the corporate LAN over VPN).

Any idea how to solve this problem (please let me know what to search
for if this information is in available in previous postings)?

Thanks...

-Noralf-