You would have to get an older version of AE to do that. If you'll look in the help documents for CS5.5, you will see that those formats are not supported for import or export.
What Szalam says.
In addition, you should know that AE comes close to being the world's WORST audio editing application. It's much better to use audio tracks in AE for timing purposes, and to do the REAL audio editing in a different application.
You get used to the workflow after a while.
Yes, I realized that. I time up my animation in AE and then I send the soundwork to protools. You can import an AE project into premier and save an OMF but it´s better to time it again in Premiere. I understand now how it works Thanks for replying.