sorry, i'm working.. can't chat.. i can only give you an idea on how to do this if you want the process to go directly to an account and not keep the users credit card number which will make them feel secure.
first, your bank should support online CC processing like paypal does.
second, look for the banks API on its website and read the instructions on how to use it and its commands.
one of the most important thing you should now is the codes and error codes for the transaction and at the same time the server to which you will communicate. usually there are 2 types of server, sandbox/test servers and there are production servers.
So basically, you should know the codes and to which server you should connect for processing communication.
then your next problem is how to communicate with that server.(POST/GET)
thats its.. then research, research, research.. if you're using an opensource, you should look for a module which supports that kind of payment module..
BOW....