Triggering lookup when calc on related data change

Alright, maybe someone can figure out if this can work:

I have a database of solicitations, in which there is a calc field that sums transactions in another database flagged with a particular solicitation name to get a total for said solicitation [sum(Transactions by k_Solicitations::c_CurrentValue)].

This then feeds into a "dashboard" viewer database through a portal, which is obviously a bit of a strain on the system and one's patience... sloooooowwwwwww! I'm trying to come up with a way to create lookups for these calcs, so they display more easily. However, the usual mod-key trigger tricks don't work, since the actual solicitation record is not being modified... only the calcs on a related field in another DB. Is there a method to trigger a lookup in one database, when related data in another that feeds calcs changes? IE, if someone enters a $100 transaction in the transactions DB, the sum calc fires... can that trigger a lookup somehow?

Thanks in advance for taking a crack at this!

Tech specs:

This is a solution running on mixed Mac OS environment (9 & X), using FM5.5