pptp vpn through another pptp vpn

i want to use pptp vpn connection through another pptp vpn connection. one is needed for connecting to internet (the accounting server in my office) and the other one is used for security or other purposes. in Linux i can use only 1 pptp connection. is there anyway to create a pptp vpn connection through another one?

You are realy needed to use pptp connection to office or you needed any of kind the secure tunnel to office? Can you use IPSEC (net-firewall/ipsec-tools)?

sometimes i use it for security and sometimes for other reasons. for example, we should use it when we want to download papers from journals that are available from specific library and we should use pptp vpn connection to that library which is out of our office.