I highly doubt it..most mass-produced PCs from large companies have very little you can change in the BIOS. You could get into the BIOS and check to be sure..but I really doubt there will be much you can do, unfortunately.
It is unlikely that there are settings in the Dell BIOS to support changing the CPU voltage. But it is worthwhile to check to see if the settings are there. Your CPU should operate at a voltage between .8-1.375 V. check ARK for your CPU’s voltage specs. If you cannot change the voltage in the BIOS your only option is to get a new 1366 motherboard.