I too am looking for this ability.
Using LiveCycle ES2 (9), I want to make a submit button that will open the default email program (in this case outlook) and have the subject line with, "Name _of_my Document" plus the text in the filled object currently called, "TextField4".
Based on the help here and on another thread similar, I am still not able to get this properly set up. I have a button, I have it launching to email properly with the fill form as a.pdf, but don't know what code to place into it so that subject line calls out the one particular field I want.
Could some kind soul please provide more detail as it relates to my version of LiveCycle?