Converta PHP scipt into a C# DLL

Currently the script connects to a MySQL server, performs queries, formats the QBXML, and then displays the results. The XML is in the php script, the DLL just needs to plug in the values and return the XML. We also need to be able to pass a connection string into the DLL when the class is initialized for interoperability reasons. From the dev on our side: 'I need a (one and only one) C# file that has a function to mark an invoice as complete and a function to load [login to view URL] with the EXACT same QBXML that the website does.' The expected class would look something like this: public class OrderData { private string _cust; public string Customer { get { return _cust; } set { _cust = value; } } private string _email; public string Email { get { return _email; } set { _email = value; } } private string _fax; public string Fax { get { return _fax; } set { _fax = value; } } private string _markasdone; public string MarkAsDone { get { return _markasdone; } set { _markasdone = value; } } private string _order; public string Order { get { return _order; } set { _order = value; } } private int _ordernum; public int OrderNumber { get { return _ordernum; } set { _ordernum = value; } } private string _payment; public string Payment { get { return _payment; } set { _payment = value; } } private string _cvv2; public string CVV2 { get { return _cvv2; } set { _cvv2 = value; } } private string _phone; public string Phone { get { return _phone; } set { _phone = value; } } }