Using a Flash Banner/Embed as a Community Header?

[bravelioness]

Hey there guys! ^_^/

I've often commented here before helping others out, but this is my first time actually posting an entry here! I guess this day had to come some time, didn't it? =P

Anyway, I run a community on here that has been gaining members by the day, and recently the other admin and I were working on a very beautiful flash banner for the top of the comm, to be used as a header. But despite all the things I've tried, I simply cannot find a way to actually have it show up as the header image! >.< Usually when I try to add the file as a banner, it removes the custom layout I have up entirely! O.o

Does anyone know if it's possible to put a .swf file or an embed at the top of a community, as a sort of header? And if so, how is that done? 

Thank you so much for anyone who can help! I know if we can get this working, it will be a treat for all the members on the community! ^_^v

Edit: I should mention, I am using a custom-made Flexible Squares layout! The other I might consider is Smooth Sailing...In case that helps! ^^