/nsg arent a command in mirc, i guess you meen /msg, how ever you can hide that text by add a . .. /.msg nick message here . and add this to your remote (ALT + R in mirc) you maybe halt the text you see in the status window when list channels:
raw 321:*: { haltdef }
raw 322:*: { haltdef }
raw 323:*: { haltdef }
