Can someone help me with this hack/feature to my forum?

[EvilLS1]

In admin/functions.php find:

if ($post[customtitle]==2) {
			$post[usertitle] = htmlspecialchars($post[usertitle]);
		}

Below it add:

// first profile field
if ($post[fieldX]!="") {
$gamedata1="<smallfont><b>Currently Playing:</b><br>$post[fieldX]</smallfont><br>";
} else {
$gamedata1="";
}

// second profile field
if ($post[fieldX]!="") {
$gamedata2="<smallfont><b>Xbox Live gamer tag:</b><br>$post[fieldX]</smallfont><br>";
} else {
$gamedata2="";
}

Note: In the code above, replace ALL Xs in "$post[fieldX]" with the field IDs for the two fields you added. There are 4 places that will need to be changed to your field IDs. $gamedata1 is for the first field, and $gamedata2 is for the second.

Now go to your postbit template and remove all of the code & text that you added earlier.. Now replace it with:
$gamedata1
$gamedata2

That should work.