//Prototyp
extern "C" _declspec(dllexport) int _stdcall Addition(int Zahl1, int Zahl2);
 
//Funktion
extern "C" _declspec(dllexport) int _stdcall Addition(int Zahl1, int Zahl2)
{
  int hui = Zahl1 + Zahl2;
  return hui;
}

Private Declare Function Addition Lib "vbdll.dll" Alias "Addition" (Zahl1 As _
  Integer, Zahl2 As Integer) As Integer
 
Private Sub Command1_Click()
    MsgBox Addition(5, 6)
End Sub