Joomla User Registration add extra fields with validation

Looking for developer to start immediately. I have a joomla website that needs a additional field added to the user signup. This field will need to validate a code listed in a table in joomla it will also need to disable code once it is used in the system. Table will have the following three fields idx,code,active (idx-primary key, code-8 digit, active 1,0 field) When the user signs up they will need to add the following information: Name Username Code Password Verify Password Email The (Code) will valicate from the jos_codes table that I already have built with codes in it. The system should also show the code in the users information in backend of joomla.