You want to connect to internet from the phone using your SLT connection? Do you have a wireless router (or a laptop with a wireless adapter)? If so, then that is the easiest way, just create a Wireless AP and you are done.
If you don't have a Wireless router then I think you can use BT instead. At least there was an app called GNUbox for S60V3 devices, maybe it'll work with S60v5 too, but I haven't tried it.