Michelle, I am not an expert, only a hobbyist. However, I will try to help you until someone better qualified offers assistance.
It appears to me that your info is faulty, to a degree. To the best of my knowledge, there would have been no unit designated a "Bomber Squad". Perhaps you were refering to a "Bombardment (or Bomber) Squadron" of the US Army Air Force? If that was the case, from info found at this web site
it appears there was no Squadron with that numerical designation. There was, however, a 384th Bombardment Group. At the web site listed above, you can find that their campaigns were: Air Offensive, Europe,Normandy,Northern France,Rhineland,Central Europe,Ardennes-Alsace (Incidentally, I am not familiar with the term "Atiennes" listed in your post.)
If you can not positively establish his unit from info you already have, you might first try to get his personnel record from NPRC. They had a disastrous fire in 1973 and many records were lost, but you might be one of the lucky ones whose forebear's records survivied. More info on how to go about doing so can be found at this web page: