I hope I am posting this in the correct area?
I have a vigor 2820.

I have a problem that im not sure how to fix, or if I can even do what I need to do with the 2820.

I have created 2 VPNs for home workers with no problems all working fine.
I now have to create a new VPN for access into a customers network. The problem is that we have got the same private IP address range as another 3rd party that connects to the customer.

Our IP range is 192.168.254.0/25

This is where my lack on network knowledge kicks in.

I only need to use 1 physical PC for the new VPN so is there anyway I can setup a second network range

i.e. 192.168.77.0

on the same physical network and get the Vigor to recognise this and my 254.0 range and route them both to the internet and then just specify the 77.0 for the VPN.

Or is there a better or correct way of solving this problem with this device or do I need additional devices?

Im under time pressure to get this sorted out so any help would be greatly appreciated.

Thanks.