no no no. always ALWAYS enclose paths to files and folders in quotes. I suppose I should have done that in my example, so that's my fault. your path has spaces, which won't actually return the full path when put to use, unless you put it in quotes.

Code:
on *:text:@[JP]Rina-Uchiyama:#abcd:{ 
  var %num = $rand(1,$findfile("C:\Documents and Settings\FaBiAn\My Documents\My Pictures\Rina Uchiyama",*.*,0)) 
  var %file = $+(",$findfile("C:\Documents and Settings\FaBiAn\My Documents\My Pictures\Rina Uchiyama",*.*,%num),") 
  dcc send $nick %file
}


there ya go.

-Venoman