Setting 'nice' level for specific binary

[Chris]

Is there a way to globally force a lower priority ('nice' level) on a 
specific binary executable, that technically can be called from any cgi-bin 
directory on a single server, where each copy is owned by a different 
hosting user?  The filename is unique so we can assume any requests to this 
same filename are for the same binary file.  I'd like to experiment with 
re-nicing a particular hosted application that at times creates such 
incredibly high CPU loads that everything else stops responding (httpd, 
sshd, etc) and you can't even log on to kill these processes.  This 
typically requires a hard reboot to get things working again.  Because of 
that I implemented scripts that monitor server load and when things get 
hairy (server loads exceeding 100+) they stop certain services to give this 
particular app a chance to exit gracefully, which works for the most part. 
But it can still take 60-120+ seconds at this type of loads to do anything. 
Would be nice to run this particular app, many copies of it that is, at 
lower nice level so we can at least SSH to the server when the load gets 
this high.  I'd rather have my scripts send me an SMS message when things 
get hairy but be able to log on via SSH and at least manually control this 
app at that point, rather than mucking with other services to free up 
resources.

Thank you,

Chris