Write a message into the Callstack

Hello
I am developing my own Debug Engine in VS 2010 (not Concord!).
So far everything is working fine.
For technical (& performance) limitations my engine can only retrieve a limited size callstack.
And I would like to write a notification into the Callstack Window, that the user exceeded the stack limit.
In IDebugThread.EnumFrameInfo() my engine gets asked for the IEnumDebugFrameInfo2 enumObject. This requires me to create some FRAMEINFO structs and transform them into this enumeration type. For my normal callstack this works fine, but now I want to create a greyed out entry with the "stacklimit exceeded" text.
The documentation about FRAMEINFO and FRAMEINFO_FLAGS is pretty poor (same parameters described several times, and I see different members & flags when I debug).
I played around with the entries and managed to get empty entries that crash when I click them :(
Can anyone give me a hint how to create such a user message in there (that does not crash)?
Regards,
Belkar