multiple prerun commands?

Hi all, I have hdup mounting and unmounting a partition to do backups
on to with the 'prerun' and 'postrun' settings, and it works great.

Some backups are large however, and I'd like to have hdup rm some of
the old backups before attempting another, as the new ones fail w/o
enough HD space.

I tried seperating the two commands with both ';' as per the shell and
',' like in include/exclude paths, but I couldn't get either to work.
Has anyone done this before? How did you get it to work?

Thanks,

-tom