Advanced Selection Criteria (C#)

Look at the attached simple database diagram. I want to design an advanced selection criteria for fetching records from an employee’s table. The required output is the SQL Statement in string. Upon an execution, it should return rows from an employee table based on the user selection. User should be able to select - 1. Single Employee Number or range of employee numbers or few specific employees. 2. Single Cost Centre or range of Cost Centre or few specific Cost Centre. 3. Single Business Area or range of Business Area or few specific Business Area. 4. Single Location Code or range of Location Code or few specific Location Code. While selecting value for each field, it should provide easy search functionality in code & name. To give you some guideline, our current interface is also attached. The screen shot is from windows application but we need it in web page. The current interface supports range only. When you click on? It will open a pop-up to enable a user to select desired value.