I already have search a lot the best way to do so.
I ended up with a script that
- extract inventory data from the device management tool (for me that was HP thin clients thus I extrat the data from the HP DeviceManager database)
- create an .OCS file for each device
- import generated .OCS files into OCS Server using ocs perl injector.
I am doing the same thing for other thin client types (ie : Wyse with ThinOS -> data extracted from WDM).