I assume you are referring to the OCUM vApp?
If so you won't be too lucky. The OCUM vApp is a hardened and closed system. It only contains packages that are needed for OCUM and its services to run. It's actually not meant to install and run scripts in the vApp as you cannot manage installed packages or access to certain parts of that vApp.
If you are heavily into using alert scripts and twaeking OCUM behavior, I highly recommend to install the OCUM package on a regular Linux (or Windows) OS. You then can install and use any package available for that distribution, including your preferred perl and sendmail version.