Is it possible to push out the DC9 agent to a remote site without user intervention?

We have a number of sites that we don't have remote control access to the pc's (Win7Pro). Sites are small (<5 machines and in workgroup mode) , users do not have local admin rights. IP addresses are known so is a local admin account password.

We recently trialled another product which allowed an out bound install by opening up a couple of ports on the remote site firewall , forwarded to one pc at a time. A push install was then initiated from the Control Server to the remote sites external IP address. The target pc then 'phoned home' , downloaded and installed the agent. Once the agent was installed on all the sites machines the firewall ports were closed off.

The pc's locally installed firewall is also not an issue as it is centrally controlled through policies.