load division for combocase

[borja1980]

hi. i am doing the analisis of the superstructure of a bridge and i have to check that the internal forces in the deck due to a certain moving vehicle are at least ten per cent inferior respect at the internal forces due to the design vehicle. i have come to the conclusion that i could define a combocase as design vehicle divided by certain moving vehicle and check, for the diferent internal forces, that the value for the internal force is greater than 1.1
. however, sap2000 does not seem to have that option available, because, when defining acombo, i can not. divide the load cases that conform the combocase. does anybody know how could it be done?
thanks