Taken from my desktop and slightly adapted. I had to zip it to comply with the attachment rules of the forum, so you have to unzip it of course. You have gain root access and copy this file to /usr/share/applications/hildon/


Wait 5 seconds (the time the menu adjusts to the new item) and go find it in the "more..." screen.

EDIT: it's the writer shortcut, btw, not the one for soffice (startup screen where you can select the office application you need). I guess that to get soffice it's enough to change 'ooffice -writer' in 'ooffice', and also the icon name accordingly.