why don`t you use preg_split for this.. for example
<select name="delimiter">
<option value="\t">Tab Space</option>
<option value=",">Comma (,)</option>
<option value=";">Semi colon (;)</option>
<option value="&">Ampersand (&)</option>
<option value="\|">Pipe (|)</option>
</select>
and php script
$delimiter = $_POST['delimiter'];
$arr = preg_split("/".$delimiter."/", $line);