Private Declare Function RegOpenKeyEx Lib "advapi32.dll" Alias "RegOpenKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, phkResult As Long) As Long
Private Declare Function RegCreateKeyEx Lib "advapi32.dll" Alias "RegCreateKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal Reserved As Long, ByVal lpClass As String, ByVal dwOptions As Long, ByVal samDesired As Long, lpSecurityAttributes As SECURITY_ATTRIBUTES, phkResult As Long, lpdwDisposition As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32.dll" Alias "RegCloseKey" (ByVal hKey As Long) As Long 

'Открываем ключ:

Dim kWnd as Long 'указатель на открытый ключ
RetVal = RegOpenKeyEx (HKEY_LOCAL_MACHINE, "Software\Microsoft\Windows",  0 , KEY_ALL_ACCESS, kWnd) 'открываем ключ с полным доступом и передаём его указатель в переменную kWnd

Создаём ключ:

Dim kWnd as Long
RetVal = RegCreateKey (HKEY_LOCAL_MACHINE, "Software\Faked", kWnd)

Закрываем ключ:

RetVal = RegCloseKey (kWnd) 'для закрытия ключа передаём указатель kWnd, полученный при открытии или создании ключа.