Obtaining additional information in $self in RT::CustomFieldValues::External

I’m trying to populate a custom field with data from an sql database. What I want to do is get a list of servers and place them in the customfield for a given requestor. If no request exists I can then take a peak at the current user. The issue is however, that the RT::CustomFieldValues::External contains almost no information about the environment that this particular customfield is in, if it’s a ticket, queue, or user. I’m wondering if anyone has made changes to RT in order to get more information?

I have a request into sales@bestpractical, but was hoping someone here would have been through this before. Jibsheet on irc.perl.org:#rt said I should be able to trace my way back from Elements/CustomFieldValueSelect, but I’m having a bit of trouble working my way back from there to find a point where I can add additional data into the object.

I would appreciate any thoughts or ideas on this.

-Joel