If you go to your template editor and edit your showthread template...
Then copy and paste the "top" part of the file here I can look through it and suggest a location you could put the code.
If you could copy and paste everything in showthread above:
Code:
<li><a href="poll.php?{vb:raw session.sessionurl}do=newpoll&t={vb:raw threadid}">{vb:rawphrase add_a_poll_to_this_thread}…</a></li>
</vb:if>
</ul>
</li>