Well I'm not sure about the resistor unless its to create a filter of a higher order. Anyway I took one of the Vandersteen filters apart and found two caps in parallel which sum the capacitance, but no resistor. If the resistor is in series than I think you would add it to the capacitive impedance, if in paralel than its 1/Z = 1/Xc + 1/Xr where Xc is capacative reactance and Xr is resistance reactance. This is where a spreadsheet comes in handy. Again I'm no expert, but I think this is how it goes.