Open a part invisibly while drawing is already open

Hi,

Does anyone have any idea of how to open a part in the background while a drawing is already opened?

I'm trying this: 2017 SOLIDWORKS API Help - Keep SOLIDWORKS Invisible While Activating Documents Example VB

but it seems to work only if SolidWorks is closed (and a drawing is not open).

Any ideas?

Thanks

SolidworksApi macros