Adding in-memory assembly to referenced assemblies

Question

Hi, I have a problem concerning in-memory compilation.

I first generate an in-memory assembly of some source code describing an interface.
I then want to generate an in-memory assembly of some source code describing a class implementing that interface. I don't want to store the interface assembly as a file on the disk temporarily during the last compilation process (which seems my only option...)

Any suggestions?

Thank you for your attention!

Best regards,
Ezzymann