cron jobs and LC server

[jbv at souslelogo.com]

Hi list
I need to run a cron job every 5 minutes to process
some data on a server and the job needs to stop when
all data are processed. The thing is : the data will be
posted only once or twice a month and it is impossible
to predict when.
So my idea is to set up a cron job automatically when
needed and remove it when all data are processed.

I found the following tutorial :
http://www.thesitewizard.com/general/set-cron-job.shtml
Before I make a big mistake I thought it would be wise to
ask specialists on this list if it would be safe to do that from
within a LC server script...
The idea is : a specific LC script would be used to set up and
remove the cron, which in turn would trigger another script
every 5 min to process data.

Thanks.
jbv