EXS 24 Logic Sampler Users Group

I'm trying to archieve a song for PC on my Mac. The EXS doesn't 
translate easily...these are my problems.
1)PC EXS can't find sample instrument-I found out that you have to 
rename the sample instrument .EXS - Do I have to do this to every 
sample instrument that I load to a PC from a Mac?
2)PC EXS doesn't alocate the samples to the proper location 
stipulated by the sample instrument e.g. After adding the 
extention .exs, I can now see "909 kit.exs". But, When I load the 
sample instrument I get a warning saying that there is no "909 kick". 
When I open the editor and click the sample name the sample folder 
pops up full of 909 samples...none have been assigned...WHY? Do 
samples have to be .wav for allocation purposes (these samples happen 
to be .aif). There has go to be an easy and efficiant way...Help!
Thanks, Mitch