FIND ERROR: Converting Segment address to segment number ?

Hi,

somebody said here that "Find Error" wants to get the segment number
but the default exception handler gives the segment address.

Can't we rewrite the default exception handler?  Does anybody know the
code for converting the address to the number?

BTW: Did somebody find an error with find error ?  I tried this about
20 times, but it worked NEVER! (Yes, I have a [detailed] .map file!)