Do you mean the plugin's "shortcode" ?
I can see that of the ask page in the shortcode-q2a.php, line 189.
If you just extract the html and paste it somewhere in wp, it should work...
<div class="qa-ask-box group">
<form method="POST" action="
http://www.question2answer.org/qa/ask">
<table>
<tr>
<td>
<label>Ask a question</label>
</td>
<td>
<input name="title" type="text" placeholder="write question title and hit enter...">
</td>
</tr>
</table>
</form>
</div>
(of course you should adapt the css)
About the plugin, I've never tried to install and use it (I don't have wp)