Connecting Switches to Hidden Supply Pins in Proteus ISIS

I am currently working on a simple circuit involving logic gates in Proteus ISIS from Labcenter. By default, the power pins are hidden. You can access them by right-clicking the component, selecting "Edit properties", and going to "Hidden pins". You can then select the power supply you want to use. However, for this particular circuit I am attempting to put a switch between the power supply and the chip's VDD pin, and another switch between the VSS pin and ground (I know this switch is not necessarily needed, and probably should not even be used, but this is just an experiment). Is there a way to do this? Whenever I add in a different netlist name for VDD and VSS when editing the component properties I get errors saying No power supply specified for net in Power Rail Configuration.

I am using Proteus 7 Professional. I don't think a schematic would be all that helpful at this point, but let me know if you need it. Basically I just need switches between VDD and +5V and between VSS and GND.