Code:

unit C_rcmemo;

interface

uses

SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,

Forms, Dialogs, StdCtrls;

type

TRCMemo = class(TMemo)

private

   { Private declarations }

   function GetRow: Integer;

   procedure SetRow(value: Integer);

   function GetCol: Integer;

   procedure SetCol(value: Integer);

   function GetPosn: LongInt;

   procedure SetPosn(value: LongInt);

protected

   { Protected declarations }

public

   { Public declarations }

published

   { Published declarations }

   property Row: Integer read GetRow write SetRow;

   property Col: Integer read GetCol write SetCol;

   property Posn: LongInt read GetPosn write SetPosn;

end;

procedure Register;

implementation

function TRCMemo.GetRow: Integer;

begin

Result := Perform(EM_LINEFROMCHAR, $FFFF, 0);

end;

procedure TRCMemo.SetRow(value: Integer);

begin

SelStart := GetCol + Perform(EM_LINEINDEX, Value, 0);

end;

function TRCMemo.GetCol: Integer;

begin

Result := SelStart - Perform(EM_LINEINDEX, GetRow, 0);

end;

procedure TRCMemo.SetCol(value: Integer);

begin

SelStart := Perform(EM_LINEINDEX, GetRow, 0) + Value;

end;

function TRCMemo.GetPosn: LongInt;

var

ro, co: Integer;

begin

ro := GetRow;

co := SelStart - Perform(EM_LINEINDEX, ro, 0);

Result := MakeLong(co, ro);

end;

procedure TRCMemo.SetPosn(value: LongInt);

begin

SelStart := Perform(EM_LINEINDEX, HiWord(Value), 0) + LoWord(Value);

end;

procedure Register;

begin

RegisterComponents('NJR', [TRCMemo]);

end;

end.