Precision 5770 compatible pen

These should work with a standard capacitive stylus as a stand-in for your fingertip.

The system will not afford active pen support (i.e., if you're looking for pressure sensitivity and precision handwriting or drawing, this is the wrong system for that).  This model doesn't have an active digitizer that a pressure-sensitive active pen requires.  For that you need a 2-in-1 system with an active digitizer display -- either an XPS 13 or an Inspiron system with that type of screen.