Use the CaretLine and CaretPos properties to determine the caret's position. The CaretPos property is 0-based. The first character in a line is 0. Use the TextLine property to get the line based on its index. Use the DeleteLine method to delete a line given its index. Use the CaretPosX and CaretPosY properties to get the pixels coordinates of the control's caret relative to the control's client area. Use the ClientToCursor property to determine the line from cursor. Use the CaretPos to ensure that specified character fits the control's client area. Use the EnsureVisibleLine method to ensure that a line fits the control's client area.