Refernce to Obejct

[matscherYAYGA]

Hello there, 

I have the current problem that i have to find the Workplane in a family instance. 

I get the Refernce by name with the .GetReferenceByName with this i have the Reference. The problem is that i have to get the ReferencePlane object from this refernce because in the reference there id is the FamilyInstanceID

Thanks in advance