Wordpress existing plugin alter (php and mysql required)

Plugin I need to alter is [login to view URL] ? Tasks: 1. add a new type 2. insert submited (sent) data in the database table as well.? If the field id has multiple values, it should be stored for easy query of database.? (I prefer to insert the details in the existing db and not to publish the database username and password in this script) (this plugin allow creation of multiple forms. I would like to submit into database only some of the forms (wich will match db fields), and I'd like not to submit into database all the other forms will be created (ie. a contact us form) How to do that ? 3. construct a sql filter query to search the database table. The query should return the list with the required field id and be able to apply the conditions: "AND" and "OR" operator for the fields and values. An example would be fine detailing how to apply a filter. Alternatively you may create a separate php filtering page for this which exports a csv file with the required filed. Let me know if you can do this and I give you more details.