rightnow report dynamic drop down

Summary: How to dynamically filter out drop-down values within a Report

I have a custom object named StoreUsers with 3 columns: ID, AccountID, Name. I have setup a parent-child relation with the Accounts table so 1 Account may have multiple StoreUsers. The StoreUsers has >1000 records. I want to use it (StoreUsers) as a drop down filter on a custom report, but I want to filter out all records except those where AccountID = LoggedIn User.

A better approach would be to have AccountID & StoreUser as filters in the report and based on the AccountID selection, the StoreUsers returns only the related records.

Any idea how to implement that?