I would be surprised if you could bypass the calibration step. I think you are better off buying a stylus for the DR800 - especially because most functions are much faster to access with a stylus, and some functions are only accessible that way (search, jump to page, etc.)
The key words to look out for are "Wacom Penabled".
This pen from Amazon, for example, is quite cheap and I can confirm that it works, having bought one myself for my DR800.