Dim zeilen() as string
zeilen = split(Textbox.text, vbcrlf)

dim i,j as integer
dim worte() as string
dim text as string
for i = 0 to ubound(zeilen)
  worte = split(zeilen(i), " ")
  if worte(0) = "PRINT" then
    for j = 1 to ubound(worte) 
      text = text + " " + worte(i)
    next j
    <text ausgeben>
  end if
next i