hook location for breadcrumbs template?

[mooreaa]

I dropped the following code into a custom template called simple_breadcrumbs:

<!-- breadcrumb -->
<table cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%">
	<tr>
		<td>
		<table cellpadding="0" cellspacing="0" border="0" width="100%">
			<tr valign="bottom">
<td>
<a href="#" onclick="history.back(1); return false;"><img src="$stylevar[imgdir_misc]/navbits_start.gif" alt="$vbphrase[go_back]" border="0" /></a></td>
				<td>&nbsp;</td>
				<td width="100%"><span class="navbar"><a href="$vboptions[forumhome].php?$session[sessionurl]" accesskey="1">$vboptions[bbtitle]</a></span> $navbits[breadcrumb]				</td>
			</tr>
		</table>			
		</td>	
	</tr>
</table>
<!-- / breadcrumb -->

in my plugin I am trying to call: eval('$simple_breadcrumbs = "' . fetch_template('simple_breadcrumbs') . '";');

and I also have the necessary bit for the template cache, but I'm not sure where to hook this in.

From various templates I add $simple_breadcrumbs to call the template.

I looked at the "navbar below forum posts" example, and theirs only gets called when you view threads. I tried various hook locations forumdata_* global_*, etc but it looks like the $navbits never populate correctly