Sure, with the php cli which ispconfig requires to be installed anyway (at least, in the debian server setup).
Since it is on a command line, it will work as long as your file system can be read, etc. just like a bash script, perl script, etc.
As a bonus, the 30 second time limit and memory limits don't apply.
You may want/need to make a copy of the script and specify php as the handler, remove HTML output, etc. instead of just running the script as-is
Remember that cron will send any output/errors to local email, so you may want to have no output and just let the php script send/call.