'make a new project: one form with a commandcontrol
'insert the code on the right places
'make the nessecary changes concerning your application and extension
'look for the * sign!

Declare Function RegCreateKey& Lib "advapi32.DLL" 
alias
 "RegCreateKeyA" (ByVal hKey&, ByVal lpszSubKey$, lphKey&)
Declare Function RegSetValue& Lib "advapi32.DLL" 
alias
 "RegSetValueA" (ByVal hKey&, ByVal lpszSubKey$, ByVal fdwType&, ByVal lpszValue$, ByVal dwLength&)

' 
return
 codes from Registration functions.
Public Const ERROR_SUCCESS = 0&
Public Const ERROR_BADDB = 1&
Public Const ERROR_BADKEY = 2&
Public Const ERROR_CANTOPEN = 3&
Public Const ERROR_CANTREAD = 4&

Public Const ERROR_CANTWRITE = 5&
Public Const ERROR_OUTOFMEMORY = 6&
Public Const ERROR_INVALID_PARAMETER = 7&
Public Const ERROR_ACCESS_DENIED = 8&

Global Const HKEY_CLASSES_ROOT = &H80000000
Public Const MAX_PATH = 256&
Public Const REG_SZ = 1


Private 
sub
 Command1_Click()
    
dim
 sKeyName As String   'Holds Key 
name
 in registry.
    
dim
 sKeyValue As String  'Holds Key Value in registry.
    
dim
 ret&                 'Holds error 
status
 if any from API calls.

    
dim
 lphKey&              'Holds created key handle from RegCreateKey.

    'This creates a 
root
 entry called "MyApp".
    sKeyName = "MyApp" '*
    sKeyValue = "My Application" '*
    ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
    ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)

    'This creates a 
root
 entry called .BAR associated with "MyApp".
    sKeyName = ".bar" '*
    sKeyValue = "MyApp" '*
    ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)

    ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)

    'This 
sets
 the command line for "MyApp".
    sKeyName = "MyApp" '*
    sKeyValue = "notepad.exe %1" '*
    ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
    ret& = RegSetValue&(lphKey&, "shell\open\command", REG_SZ, sKeyValue, MAX_PATH)

End Sub