Code:
on   $*:text:/(,away|away,)/i:#yourchannel:{ set %play.list $remtok(%play.list,$nick,1,44) }
on $*:action:/(,away|away,)/i:#yourchannel:{ set %play.list $remtok(%play.list,$nick,1,44) }
raw 301:$($me *):{                           set %play.list $remtok(%play.list,$2,1,44) }

^
I assume you wasnted it if the away had a comma at the front or the back or both rather than just "away" in the text. If it was just "away" in the text then its the below...

Code:
on   *:text:*away*:#yourchannel:{ set %play.list $remtok(%play.list,$nick,1,44) }
on *:action:*away*:#yourchannel:{ set %play.list $remtok(%play.list,$nick,1,44) }
raw 301:$($me *):{                set %play.list $remtok(%play.list,$2,1,44) }


The raw 301 is just what i encountered when someone IS away, but only when you try and msg them, before that you cant tell there away, so there is no on the spot method of detecting someone going /away (that i know of)