Make a small script for it.
************************************
Chase.sqs
_chasee = _this select 0
_pursuer = _this select 1
_pursuer dofire _chasee
#update
_cpos = getpos _chasee
_pursuer move _cpos
~5
NOT ALIVE _pursuer: goto "exit"
~30
goto "update"
#exit
exit
*************************
I guess something like that, you can change the time values, these values are if the chase is over a large area. Smaller values for a quicker chase, so the pursuer has an almost constant changing target place to go. Or maybe a basic Destroy waypoint might do it....
Oh yeah script called like this...
[bobbybruning, sergeisergunov] exec "Chase.sqs"