Get source from Drag & Drop

I have an application where I pass data through the Drag & Drop event from Form A to Form B like so:

// FormA.cs
private void g_SelectionDrag(object sender, CancelEventArgs e)
{
   string path = Path.ChangeExtension(Path.Combine(Path.GetTempFilePath(), Guid.NewGuid().ToString()), ".txt");
   DataObject dobj = new DataObject();
   dobj.SetData(DataFormats.FileDrop, new string[] { path });
   
   // only possibility?
   // dobj.SetData("MyFormat", new object[2] { this, path });

   g.DoDragDrop(dobj, DragDropEffects.Copy);
}

// FormB.cs
void c_DragDrop(object sender, DragEventArgs e)
{
   if (e.Data.GetDataPresent(DataFormats.FileDrop, true) && (e.Data.GetData(DataFormats.FileDrop, true) != null))
   {
      String[] SelectedFiles = (String[])e.Data.GetData(DataFormats.FileDrop);
      // do things with the file
   }
}  

Is there a way to receive the sender from the event (this should be FormA) inside FormB? The sender parameter in the DragDrop-event of FormB is only the control receiving the drop-action located in FormB and not the initiator of the drag-event.

Is the only possibilty to pass this with the DataObject.SetData()-function in FormA and include the file-path additionaly or can I receive the source somewhere else?