[Modin]

a simple way to do this via templates with the first one. (normally I'd do it another way, but this way is simple to do)

Add the code to your forumdisplay template

<if condition="$forumid == 4">
stuff for forumid 4
</if>
<if condition="$forumid == 5">
stuff for forumid 5
</if>
<else>
default stuff
</if>