Data over VOIP possible?

I want to connect from the Main Office using my SIP VOIP provider to a remote office (wich only has a PSTN line), but i want to use that connection to trasmit data.
The idea is that at the remote office i have a PC, i want that PC to have internet access through the sip voip connection that was previously established from the Main Office.

Is this possible? any ideas ?

Thank you very much.

forget about it