You'll need an IPSEC client for the same kind of VPN on the phone. Contact the VPN provider to see if there is one. (For instance, a client that will connect to a Cisco AnyConnect server might not connect to another VPN server.) You might try
I do know that I require an IPSEC client to connect to the remote network as that is what I use on my laptop and it works just fine. With my phone though, for some reason even after it says connected it will not access the remote network files. Btw, using a netgear fvs318v3 router.