Formatted text file Into TextMember with Scrolling... Problem.

member("MyTEXT").importFileInto(_movie.path & "mytext.rtf")

member("MyTEXT").boxType = #scroll

You can't import formatted text into a #field - that's not the way the field member type works, it doesn't support any formatting. Please explain why you say:

and It has to be a field … when the RTF is imported

Try the following, or some snippet or re-working of it, attached to your #text sprite:

property spriteNum
property my
property myMember

on beginSprite me
  my = sprite(spriteNum)
  myMember = my.member
end

on mouseUp me
  if ( myMember.text = EMPTY ) then exit
  tLoc = _mouse.mouseLoc - my.loc
  tPos = myMember.locVToLinePos(tLoc[2])
  nChars = 0
  repeat with l = 1 to tPos
    nChars = nChars + myMember.line[l].char.count
    -- account for RETURN at line end
    if l < tPos then nChars = nChars + 1
  end repeat
  
  if tLoc[2] < myMember.charPosToLoc(nChars)[2] then
    tClickedLine = tPos + myMember.scrollTop/myMember.fixedLineSpace
  end if
  
  PUT tPos, tClickedLine
end

Or what about just using pointToLine?

Adobe Director * pointToLine()