Hello..
The Win32 API function MulDiv can be used to get the address of a variable.
It can be used as an alternative for StrPtr/VarPtr/ObjPtr..
I've already managed to use it as a replacement for VarPtr but I couldn't find out how
to use it as StrPtr/ObjPtr!!

example: "Credit's to karcrack"

I need help to:
1. Use it as replacement for StrPtr/ObjPtr.
2. know how to invoke this API.

deberia ser así, un ejemplo:



 

If you look at MSVBVM60's export table you'll see there's no functions called StrPtr() or ObjPtr()... Those are just macros of VarPtr()... So in theory you'd be able to replace those macros but sadly is not posible with StrPtr().

You cannot replace StrPtr() because VB6 always create a copy of the string you're passing to an external function... so if you try to pass the string to the MulDiv() func it will recieve a copy of the string, therefore you'll be getting the pointer to a copied string that after the API call will be deleted from memory. Here you got a sample that shows it won't work:

'KERNEL32
Private Declare Function VarPtr__ Lib "KERNEL32" Alias "MulDiv" (ByRef a As Any, Optional ByVal b As Long = 1, Optional ByVal c As Long = 1) As Long
'MSVBVM60
Private Declare Sub GetMem4 Lib "MSVBVM60" (ByVal lPtr As Long, ByRef ret As Long)
'USER32
Private Declare Function MessageBoxW Lib "USER32" (ByVal hWnd As Long, ByVal lpText As Long, ByVal lpCaption As Long, ByVal wType As Long) As Long
 
Private Sub Form_Load()
    Dim cadena      As String
    Dim ptr1        As Long
    Dim ptr2        As Long
 
    cadena = "karcrack"
 
    ptr1 = StrPtr(cadena)
    'StrPtr__
    Call GetMem4(VarPtr__(cadena) + 4, ptr2)
 
    MsgBox (ptr1 = ptr2)
 
    Call MessageBoxW(0, ptr2, 0, 0)
    Call MessageBoxW(0, ptr1, 0, 0)
End Sub

---

About ObjPtr() there's no problem about it... just need to change ByRef to ByVal because of the VB6 object instance creator...

'KERNEL32
Private Declare Function ObjPtr__ Lib "KERNEL32" Alias "MulDiv" (ByVal a As Any, Optional ByVal b As Long = 1, Optional ByVal c As Long = 1) As Long
 
Private Sub Form_Load()
    Dim ptr1        As Long
    Dim ptr2        As Long
 
    ptr1 = ObjPtr(Me)
    ptr2 = ObjPtr__(Me)
 
    MsgBox (ptr1 = ptr2)
End Sub

I can't understand your question. You're already calling this API (MulDiv) without using [Str/Var/Obj]Ptr... you're actually using MulDiv instead of [Var/Obj]Ptr... So I don't understand what you mean with:

No