SSAS: Comparing Actuals and Targets at different granularity when you cant use IsLeaf()

Yesterday I inadvertantly come up with an interesting solution (in SSAS2005) to a common problem! For arguments sake say I have a simple cube containing two measure groups – one for Actuals and one for Targets. The Actuals fact contains a measure “Actual_Days_Elapsed” i.e. the number of days an event took. There are number of dimensions such as Time, Location, and Event_Group – all are related to the Actuals via regular relationships using the dimension key attribute.