Create two buttons that interact with an editbox

Hi all I hope in an answer that could help me about my problem because I'm going crazy.
I'm creating a GUI in Visual C++ .NET and I'd like to split the "Spin Control" in two buttons.

I created an editbox with a spin, only to test the code, and the result is this:
See Image1

Here the code that I wrote:
The spin control:

Code:

CSpinButtonCtrl *spin = (CSpinButtonCtrl*)GetDlgItem(IDC_SPIN_ROTOR_TEST);
         spin->SetRange(0, 25);
	 spin->SetPos(0);
GetDlgItem(IDC_ROTORTEXT)->SetWindowText("A");

The letters in the editbox:

Code:

void CTestDlg::onShowposSpinStr(NMHDR* pNMHDR, LRESULT* pResult)
{
	int nNewPos;
	char szNumber[][16] =
	{ 
		"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "W", "V", "X", "Y", "Z"
	};
	NM_UPDOWN *pNMUpDown = (NM_UPDOWN*) pNMHDR;

	nNewPos = pNMUpDown->iPos + pNMUpDown->iDelta;

	if(nNewPos >= 0 && nNewPos <= 25)
	{
		GetDlgItem(IDC_ROTOR3TEXT)->SetWindowText(szNumber[nNewPos]);
	}
	*pResult = 0;
}

But now I have to split the spin into two buttons that interact with the editbox, to increase/decrease the letters, like this:
See Image2

I have no idea on how I can do this...
Please someone help me, I'm desperate.

This morning I splitted the spin control in two buttons, here is the code:

Code:

void CTestDlg::OnBnClickedButtonUp()
{
	int rl=GetDlgItemInt(IDC_EDIT3TEXT);
	rl=rl+1;
	SetDlgItemInt(IDC_EDIT3TEXT,rl);
}

void CTestDlg::OnBnClickedButtonDown()
{
	int rl=GetDlgItemInt(IDC_EDIT3TEXT);
	rl=rl-1;
	SetDlgItemInt(IDC_EDIT3TEXT,rl);
}

But I need to display letters into the editbox not the numbers.
Obviously I need letters from A to Z.
Someone could help me to intergrate the code of the function that I created to display the letters in the first post and this?

Any help?

should of posted in HERE

Please moderators Lock or Delete this topic I moved to Windows Programming.

Thank you!