для VBA
ActiveWindow.RangeSelection.Address(False, False, xlR1C1, Nothing, Nothing)

var
  Excel: Variant;
...
Excel := CreateOleObject( 'Excel.Application');
...
Excel.ActiveWindow.RangeSelection.Address( False, False, xlR1C1, Null, Null)

  var
    Columns, Rows   : Integer;
    Code            : string;

    function A1ToIndex( A1Style: string): Integer;
    var
      i             : Integer;
    begin
      Result :=  0 ;
      for i :=  1  to Length( A1Style) do
        Result := Result + ( Ord( A1Style[ i]) - $ 40 ) +
          ( Ord( 'Z') - Ord( 'A') +  1 ) * ( i -  1 );
    end;

  begin
    Code := Copy( Address,  2 , Pos( ':', Address) -  2 );
    Columns := A1ToIndex( Copy( Code,  1 , Pos( '$', Code) -  1 ));
    Rows := StrToInt( Copy( Code, Pos( '$', Code) +  1 , Length( Code)));

    Code := Copy( Address, Pos( ':', Address) +  2 , Length( Address));
    Columns := A1ToIndex( Copy( Code,  1 , Pos( '$', Code) -  1 )) - Columns +  1 ;
    Rows := StrToInt( Copy( Code, Pos( '$', Code) +  1 , Length( Code))) -
      Rows +  1 ;