Controls in the header affecting a list in the Details

[dakcg]

I'm trying to use two controls in the Header and have a continuous form show up in the Details based on the selections in the header.
The DB has to do with multiple gas and electric meters in different units in a property. In the Header I have drop down boxes specifying Unit and Meter type, in the details I want a list of all meters associated with that Unit and Meter type so I can enter the new meter readings and calculate the usages for each meter. Any thoughts??