A bit difficult to tell.
Just share my Experience in PAL.
Create Empty or transparency bakground of 768 x 576 in PhotoShop size.
Make sure your logo has alpha chanel. Define a position where it should be.
If you don’t have, you have to make it by yourself (hope you understand how to do that. If not, you have a long way to become as a standard Editor).
Merge the layer and save it as PSD file.
Import in AVID as Maintain, Square, Single Field and 610/709 use existing or Invert Alpha.
Mine work fine.