change directory of cygwin bash from batch file

Hi all, I have a batch file(.bat file) and i want to execute the cygwin -> bash.exe from the batch file. Then i want to change the directory(of the bash) to current directory through the batch file. I am able to execute the bash.exe but not able to change the directory. Also i dont want to edit the registry. Any help would be appreciated. Thanks in advance. Regards.