How do I determine what precedent is running?

I've got some custom VBA code in MCIManExtensions.dot (in JobProcessed) that needs to know which precedent is being generated.
The code gets the value of the DocumentVariables BASEPRECID and BASEPRECTYPE, which are added to the document as it is assembled. This is all fine, unless you generate the Precedent from Outlook - it appears these variables do not get added to the document if MC is launched from Outlook.
Fistly, are you aware of the above issue?
Secondly, what should I do instead (I'd like to avoid adding our own document variables on every precedent if possible...)