So, I downloaded the technical specifications and went to the expansion slot drawing. It points at what I thought was the PCI x16 slot and it says the following:
NOTE The dc5700 platform only supports the use of normal (or non-reversed) layout ADD2 (Advanced Digital Display 2) adapter cards inserted into the SDVO (Serial Digital Video Output) connector on the platform's system board. ADD2 cards are used to give multi-monitor capabilities to the integrated graphics controller. The ADD2/SDVO connector on the system board has the physical appearance of a PCI Express x16 connector; however, the platform does NOT support the use of conventional PCI Express cards or reversed-layout ADD2 cards.
Obviously it is a no go
Thanks for at least viewing this apparently dumb question!