[Jordan]

Here is how to select an item in a listbox when right-clicking:

C++

private: System::Void listBox1_MouseDown(System::Object^  sender, System::Windows::Forms::MouseEventArgs^  e) {
          if (e->Button == System::Windows::Forms::MouseButtons::Right) {
          listBox1->SelectedIndex = listBox1->IndexFromPoint(e->X, e->Y);
 }
					
			 }

C#

private void LST_BX_MouseDown(object sender, MouseEventArgs e) {
   if(e.Button == MouseButtons.Right)
      LST_BX.SelectedIndex = LST_BX.IndexFromPoint(e.X, e.Y);
}