Question on changing and customizing User Titles

[Importhookup]

I was able to locate the postbit template in version 2.3.0 and this is the code that exists right now.

<a name="post$post[postid]"></a>
$post[firstnewinsert]
<normalfont><b>$post[username]</b></normalfont><br>
<smallfont>$post[usertitle]</smallfont><br>
$post[avatar]<p>
<smallfont>Registered: $post[joindate]<br>
Location: $post[field2]<br>
Posts: $post[posts]</smallfont></td>

I want add a custom user profile field in between the avatar and the usertitle and my problem now is I don't know what field to plug in. I know it would be $post[somethinghere] but I'm not sure what to put there. And since it's a custom user profile field it might not even be in that $post[somethinghere] format. Any suggestions?