Вариант 1

Option Explicit
Dim iKeyCode As Integer
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
iKeyCode = KeyCode
Label1.Caption = "Код нажатой клавиши: " & iKeyCode
If iKeyCode = 112 Then 'нажата клавиша F1
'Здесь вы можете вставить любую процедуру
End If
End Sub

Вариант 2

Dim temp As String
Private Sub Form_KeyPress(KeyAscii As Integer)
Dim kascci
kascci = Chr(KeyAscii)
temp = "Key Ascii = " + Str(KeyAscii) + " = " + " Char = " + kascci
If KeyAscii = 13 Then 'нажимая , вы очистите форму
Form1.Cls
Else
Print temp 'печать KeyAscii и саму букву на форме
End If
End Sub
Private Sub Form_Load()
Form1.FontSize = 12
End Sub