Can NSURL setup a POST method ?

If no, how to do this ?
A POST request can be sent using NSURLHandle writeData method.
You still have to construct the POST data:

path_to_handler_on_server HTTP/1.0
Content-type: application/x-www-form-urlencoded
size_in_bytes_of my_url_encoded_data
Note that each line terminates with a newline character and the blank line after the Content-length header.
You can build the content using classic
NSString methods and convert the resulting string into an NSData object with dataUsingEncoding.

You should also take a look at the Apple example on your hard disk:
/Developer/Examples/Networking/POST Example mixing Foundation and CoreFoundation calls to do the job.