O= CREATEOBJECT("SIM.CHARGE") should work.

You'll need hd.net.dll, interop.savcomm8.dll and log4net.dll in the same folder as sim.dll and sim.tlb.

The tlb file should have been created by com.bat

Those extra DLL's don't need RegAsm (which is what com.bat did to sim.dll)

HTH,
Mark