AFAIK you can set some variables in your crontab that will be available for the processes started by cron. Like this:

ORACLE_HOME=/path/to/oracle

20 07 * * 2-6 /home/me/bin/my_perl_script.pl
[download]

I must admit, though, that I have encoutered (linux) systems where this was not working, but on my current it does the job. Think you can configure cron to do so...

Regards

Stefan K