You can't do it on the switchboard, just do it on the form or report that
the switchboard calls.

Personally, I don't secure individual objects with passwords.  It is not
very secure, and I don't want password prompts popping up everytime an
important feature is used.  This means your most important users are the
most inconvenienced.

A better option is to implement user-level security.  Have each user sing on
one time when they open the file and then their access is set for every
object and function in the file.  They will only be able to do what you have
given them permission to do.