[BirdOPrey5]

Looking in the memberlist template the code that generates the "search members" box seems to be:

<form action="memberlist.php?do=getall" method="post">
	<table cellpadding="4" cellspacing="1" border="0">
	<tr>
		<td class="thead">$vbphrase[search_members]</td>
	</tr>
	<tr>
		<td class="vbmenu_option" title="nohilite">
			<input type="hidden" name="s" value="$session[sessionhash]" />
			<input type="hidden" name="securitytoken" value="$bbuserinfo[securitytoken]" />
			<input type="hidden" name="do" value="getall" />
			<input type="text" class="bginput" name="ausername" size="20" value="$ltr" title="$vbphrase[username]" />$gobutton
		</td>
	</tr>
</table>
</form>

I haven't tested this but replacint the navbar search code with this should do it... at least it's a start.