problem with AutoCAD type library (acad.tlb)

hi together!

does anyone know how i can send commands to extern AutoCAD applications like 3d-render via the acad.tlb interface?

there is one way in AutoCAD 2000, with SendCommands i can send text commands to the AutoCAD console, but this doesn't work in AutoCAD 14 and unfortunately the user can see my SendCommands inputs...

thanks a lot for helping!

Jonas