Try this:
Code:
on *:TEXT:!map &:#yourchannel:rcon map $remove($strip($2),.bsp)


If someone types !map blah.bsp it will send the command /rcon map blah If they type !map blah it will send /rcon map blah If they type !map the.cool.map.bsp it will send /rcon map the.cool.map

-genius_at_work