Ограничение ввода в ячейки StringGrid

//---------------------------------------------------------------------------
 
#include <vcl.h>
 
#pragma hdrstop
 
#include "StringGrid1.h"
#pragma package(smart_init)
//---------------------------------------------------------------------------
// ValidCtrCheck is used to assure that the components created do not have
// any pure virtual functions.
//
 
static inline void ValidCtrCheck(TStringGrid1 *)
{
        new TStringGrid1(NULL);
}
//---------------------------------------------------------------------------
__fastcall TStringGrid1::TStringGrid1(TComponent* Owner)
        : TStringGrid(Owner)
{
}
//---------------------------------------------------------------------------
namespace Stringgrid1
{
        void __fastcall PACKAGE Register()
        {
                 TComponentClass classes[1] = {__classid(TStringGrid1)};
                 RegisterComponents("AlphaStandard", classes, 0);
        }
}
//---------------------------------------------------------------------------
 
void __fastcall TStringGrid1::StringGrid1KeyPress(TObject *Sender, char &Key)
{
       //код пишем сюда
}
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop
#include "StringGrid1.cpp"
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
TStringGrid1 *Grid1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
         TStringGrid1 *Grid1 = new TStringGrid1(Form1);
         Grid1->Parent = Form1;
         //Grid1->Top = 70;
         Grid1->Options=Grid1->Options << goEditing;
         Grid1->OnKeyPress = StringGrid1KeyPress;
}