How to modify local group policy setting programatically

Question

I am looking for a way to programatically change the value of a group policy setting without having to reboot a machine or install any additional components on it

Looking for a solution for Windows 2003, 2008, machines are part of the domain

The value is under Administrative Templates\Network\QoS Packet Scheduler, Limit outstanding packets

Tried the following:

• Change registry directly - this doesn't work, as the value is actually stored in registry.pol file and is propagated from there to the registry

• Used WMI - WMI objects that are representing the registry are read only, value is not modified

One option that seems to work is to modify the registry.pol file underC:\Windows\System32\GroupPolicy\Machine, however this seems problematic, I will have to parse this file manually

Any insights would be appreciated