Calling all XML Experts!! - SOAP Webservice Integration with XML & Digital Cert

I'm looking to hiring someone with knowledge on creating SOAP web services, authentication using certificates and creating XML files. There is a digital certificate information involved to authenticate the form submission and this will need to be created as part of the app. I’m not exactly sure how it'll be implemented but basically we have some xsd files which contains information regarding the connection string and how to create an xml file. You will need to investigate and understand these files and figure out what needs to be done. We've got the certificates already just need a solution to connect our application with the server using the certificate and send an xml file which needs to be created programmatically as well. The project must be coded in C# in Visual Studio. You must have a static IP address as we will need to liaise with a 3rd party to add your IP to the exception firewall for testing. In summary there is a pre-existing soap service and we would like you to develop a client (software) that consume this service with our provided xsd file, and x-509 certificate file produce XML file to interact with our service from software. You know need to know how to programmatically create XML files using C# and provide good commenting on the source code. I'm expecting about 4 hours of work is required to complete this task but feel free to estimate the time frame and we can go from there. I’ve prepared a document that describes in detail what needs to be done. If you provide a good enough proposal, I will be in touch and provide you more details. Please provide some past work if you have experience in this area.