array question

This is the code I am using to get the data out of the text file below. Now I need to turn the $group[3] into an array of its own so that I can make changes to it. How do I turn this into an array that I can reference with $group[0]. What I need to be able to do is search for the label in $group[0] and then make changes to the stuff in $group[3] like delete add or change. <? $groups= file("group"); $number_in_group = count($groups); ?> <table border="1"> <? for ($i=0; $i<$number_in_group; $i++){ $group=explode(":",$groups[$i]); ?> <tr> <td><? echo$group[0]?></td> <td><? echo$group[3]?></td> </tr> <?}?> </table> The DATA site1:x:503:tester1 site2:x:504:tester2,tester2a site3:x:505:tester3,tester3a,tester3b site4:x:506:tester4 site5:x:507:tester5,tester5a,tester5b site6:x:508:tester6 site7:x:509:tester7,tester7a,tester7b -- Best regards, Richard mailto:rdkurth@starband.net