Thank you. I tried to use DSum and DLookup. This is what I did,
Dim dblPower As Double
varPower = DLookup("RatedPower", "DeviceRatedPowerQ")
Dim dblWeight As Double
varWeight = DLookup("ComponentWeight", "DeviceWeightQ")
Dim dblCost As Double
dblCost = DSum("[EuroCost]"...