I have the following HTML statement

[otsection]Wallpapers[/otsection]
WALLPAPERS GO HERE

[otsection]Videos[/otsection]
VIDEOS GO HERE

What I am trying to do is replace the [otsection] tags with an html div. The catch is I want to increment the id of the div from 1->2->3, etc..

So for example, the above statement should be translated to

Wallpapers
WALLPAPERS GO HERE

Videos
VIDEOS GO HERE

As far as I can research, the best way to do this is via a preg_replace_callback to increment the id variable between each replacement. But I just can't get it working.