I don't have a data base with military personnel on it, so there is little hope from this end in your quest for information on your Dad.
Do you or anyone in the family have a unit identification for him, like 5th. Marine Division, which participated in the reduction of Iwo Jima? Of course there were army units there too, but I haven't looked them up yet.
Hope that you are able to get back to me with more information to work with.