You're right. I was mislead by:
"The infile can be a filename or a window name (custom or normal). The outfile can be a filename or a custom window name."
and the description of the -s switch.
Actually, I even tried "/filter -ws @w1" but forgot to put a matchtext wildcard ("/filter -ww @w1 @w2" doesn't require one)
Supahsonic should use the filter command (/filter -ws @hidden *); my proposal to allow @<wid> as in/outfile still stands.
Thanks for pointing out.
