Khaled: A work-around to the SendMessage/PostMessage limitation would be possible if we had the means to use the /editbox command to populate multiple lines into multi-line editboxes. Then the batch could be sent all at once.
//window -e2 @test | editbox -n @test /whois Raccoon $crlf /whowas Raccoon
As of right now, $crlf nor $lf nor $cr can be used to stimulate multiple lines in the editbox, and it makes me very sad and gosh dang frustrated. :'(