You will run into the same problem with the BlackJack. It doesn't have any software that transforms the 26 letters of the alphabet to the corresponding digits 0 through 9. An on-screen dialer (such as that on a PPC Phone or Treo), or keyboard that has the appropriate letters masked over the numbers would be the only solutions (I've never seen one- the letters would probably be too small to see!).
I had the same problem with the Nokia E61, so I stored a JPEG photo I took of a regular number pad on the phone. I opened and displayed it on screen when I needed to know what numbers corresponded to "jones" for example on a standard numeric keypad.
-------------------- Lisa Gade Editor in Chief, MobileTechReview