fuel selector question...

I'm modeling the fuel system on a DC-9-41. There are left, right, center and center aux tanks. (see attached pic) The FS fuel tank selector switch does not allow the use of combinations such as left & center. It appears to be only left or right or both.Can I use multiple selector switches (FS allows a max of 2) and achive this tank combination?I'm thinking selector switch 1 will work the left and right tanks while selector switch 2 will work the center.I know there will need to be custom code to make this work but is this concept possible?Please help me if you see what I'm trying to do within FS contraints.ThanksJohn