How to calculate process duration?

My problem is how to get duration of a certain part of the program.
It is my program and I'll put timestamping into it myself.

So idea is:

.....
time(&Time1) ;
processing...
processing...
processing...
time(&Time2) ;
Duration = GetTimeDifference(Time1, Time2) ;

But I know, that the processing takes surely less than a second, so time() 
function, returning seconds is not OK.

Looked at mattod(). It is said, that it's tick is 1/1000 sec. Fine. But isn't 
there somewhere a way to convert _MI_Time to something usable? Or if not, can 
anyone tell me, what are the arithmetical rules for _MI_Time - I need to 
subtract one from another?


I did some bit fiddling and finally got a piece, that seems to work, but it is 
really ugly:

mattod(Time1) ;                                                      
    mitime(&WaitTime, 0, 0, 0, 50) ;  /*hours,minutes,seconds,1/100*/
    waittime(&WaitTime, _WAIT_NORMAL) ;                              
mattod(Time2) ;                                                      
memcpy(Buf, &Time1, 8) ;                                             
memcpy(&Tim11, Buf, 4) ;                                             
memcpy(&TimShift, &Buf[4], 4) ;                                      
Tim12 = TimShift >> 22 ;                                             
memcpy(Buf, &Time2, 8) ;                                             
memcpy(&Tim21, Buf, 4) ;                                             
memcpy(&TimShift, &Buf[4], 4) ;                                      
Tim22 = TimShift >> 22 ;                                             
Diff = (Tim21 - Tim11) * 1000 + Tim22 - Tim12 ;                      
printf("Diff : %d ms\n", Diff) ;                                     

The idea of mitime and waittime is simply to compare printed result to 500ms 
delay.
Isn't it ugly?
Is it the only way?

TIA,

Jevgeni Astanovski