Which windows exactly though? Status window? All windows on that server?
Status window only: echo $color(notice).dd -ts $+(-,$nick,-) $1-
All windows: var %wins = $window(*,0) | while (%wins) { if (@* !iswm $window(*,%wins)) { echo $color(notice).dd -t $+(-,$nick,-) $1- | dec %wins }
All channel windows: var %wins = $chan(0) | while (%wins) { echo $color(notice).dd -t $chan(%wins) $+(-,$nick,-) $1- | dec %wins }
etc.
You might also check your options because that lets you decide where notices go by default.
