outside-process error handling

I have a program (a c++ program) that handles fatal errors in other programs using WaitForDebugEvent in a seperate thread-loop. it works very well but the problem is :
When VB application has a (VB) fatal error, it always raises the same exception (Float inexact rezults) in the DEBUG_EVENT structue, no matter what is the error. that's probobly because VB does some error handleing of it's own before raising a system exception. is there a way to know what the (VB) error is ?
I have tryed reading it from the error Dialog-Box but the Dialog-Box does not always raised when the VB program is under "Debugging".
I have tryed reading it from the process memory but I'm not sure where.
I have tryed reading the error log, but i couldn't find any default error logging for VB programs.

any solutions ???