Posts: 153
Threads: 7
Joined: Jun 2008
Since partial copying to the clipboard requires you to move the cursor, it can only be done while editing, not directly from the history stack (at least in the current firmware). Therefore, copy the entire fraction to the edit line, then place the cursor at the beginning of the numerator, press Shift View (Copy) and tap Begin, then place the cursor at the end of the numerator and tap End, then tap Copy.
Although it does not answer your question per se, an easier way to get the numerator of the most recent result is numer(Ans).