Berlin is in Germany, I doubt the usefulness of Austrian German in Berlin, although, according to my own experiences, Germans do like the dialect and accent of Austria, although they at times confuse it with Bavarian. (Yes, I know, my answer was not really helpful, but I just had to write this. Sorry!) You better post this in the section 'discussions' or browse through 'language partners. Good luck!

It will be my pleasure to help you. Skype ID :Javad.saeidi