Catching DOS interrupt 24H (critical error handler)

[tony at joshua.math.ucla.edu]

I'd like to replace the MS DOS critical error handler with one
of my own in a C program I am writing but I can't seem to get it right.  

I've been trying to use the intdosx() function in MSC 5.1 but after 
numerous system hang-ups I've decided to ask for help.

Can somebidy explain how I can go about doing this in C?  I have
some code in assembly but I really would like to do it in C.