I have never heard any official policy about cross dressing in church. Maybe it has never been an issue but you can never know.
Has anyone ever seen a cross dresser attend a church meeting? If so, what was the reception like because we all must be treated with dignity and not be made to feel less than?
Personally, if you're a cross dresser then you have issues that need to be worked out first before you can consider the priesthood.
Under the current administration of the LDS church I can't see this being promoted or accepted in the least.