Grep works a little odd compared to Linux, but it works to filter many things.
(wlc) >grep include Not "show ap join stats summary all"
Press any key to continue..y
18:8b:9d:dd:a7:60 18:8b:9d:e3:5a:b0 r039-ap003 10.24.209.22 Not Joined
58:97:bd:10:fb:d0 18:8b:9d:df:14:28 r039-ap010 10.24.209.29 Not Joined
58:97:bd:19:a2:a0 18:8b:9d:dc:29:68 r039-ap005 10.24.209.24 Not Joined
