VPN through VPN

My AT&T digital broadband uses a VPN connection to WorldNet as my ISP. The AT&T server does not recognize or route to IP of my company VPN.

home PC VPN DUN client ->Intel AnyPoint phone line-> tranceiver==>wireless==>AT&T tower->AT&T server->Worldnet IP->Internet

VPN session between home PC and Worldnet MUST be used.
Is there a product or configuration to provide a VPN client USING the original VPN client to permit VPN from home PC, through the VPN to WorldNet, to my office VPN IP?