[Jaikis]

I think it simple...
I did it in two step:
1. Create Phrases:

Type: Global
Varname: delim_sticky
Text: Sticked threads

Type: Global
Varname: delim_normal
Text: Normal threads

2. Find this:

<if condition="$show['threads']">
<!-- show threads -->
<if condition="$show['stickies']">
$threadbits_sticky

and replace with this:

<if condition="$show['threads']">
<!-- show threads -->
<if condition="$show['stickies']">
<tr>
<td class="thead" width="100%" colspan=7><strong>$vbphrase[delim_sticky]</strong></td>
</tr>

$threadbits_sticky
<if condition="$threadbits">
<tr>
<td class="thead" width="100%" colspan=7><strong>$vbphrase[delim_normal]</strong></td>
</tr>
</if>

That's all...