COM Register: doesn't work for .NET TLB?

[wellilein]

Hello,

I am trying to register a TLB file with the COM register action.
When I try, it says:
Error loading type library: Fehler beim Laden der Typbibliothek/DLL.

When I try with .NET settings it says:
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\rega sm.exe P:\xxx.tlb /nologo /s
RegAsm : error RA0000 : Unable to locate input assembly 'P:\xxx.tlb' or one of its dependencies.

It works when I use the DOS command
REGTLB.EXE P:\xxx.tlb

Any ideas?