C#

HRESULT hr;
HMODULE hMod = NULL;
PDLLGETCLASSOBJECT proc = NULL;
IClassFactory* pFactory = NULL;

//Get the module from list or load it
hMod = GetModule( szDllPath );
if( !hMod ) return( false );

//Get Proc address
proc = (PDLLGETCLASSOBJECT) GetProcAddress( hMod, "DllGetClassObject" );
if( !proc ) return( false );

hr = proc( IInterface , IID_IClassFactory , (void**)&Factory );
if( hr || !pFactory ) return( false );

hr = pFactory->CreateInstance( NULL, IInterface , pInterface );
if( hr || !pInterface ) return( false );

pFactory->Release();

[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode]
private static extern IntPtr LoadLibrary(String lpFileName);

[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true)]
private static extern IntPtr GetProcAddress(IntPtr hModule, String procName);

[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern Boolean FreeLibrary(IntPtr hModule);

...

private static String DLLFile = string.Empty;
private static IntPtr handleDLL = IntPtr.Zero;
private static IntPtr handleProc = IntPtr.Zero;

...

DLLFile = MyPath + @"Lib\SQLQueryAS.dll";
handleDLL = LoadLibrary(DLLFile);
if (handleDLL == IntPtr.Zero) throw new Win32Exception(Marshal.GetLastWin32Error());

handleProc = GetProcAddress(handleDLL, "DllGetClassObject");
if (handleProc == IntPtr.Zero) throw new Win32Exception(Marshal.GetLastWin32Error());

???
and now
???

// This isn't giving syntax errors but doesn't work for my purposes either
public abstract class ObjectCollection<T> : Dictionary<int,T> where T : ISomeInterface, IDisposable
{
  private DataTable _sourceData;  // this is what I need IDisposable for

  public abstract LoadData(SqlCommand sourceData); // Derived classes will load data into table and base dictionary at the same time.
  
  // Class implementation...

  public void Dispose()
  {
    _sourceData?.Dispose();
  }
}