Desktop App MSSQL to MySQL

Im looking for some one to create a scipt or app that will do the following It will site on our in house server. And when we double click it or set a cron for a certain date every month it would do the following Connect to our MSSQL Database in house Take Customer name Address Product Details Total Cost Tax Costs And upload them to a office site MYSQL Database. These details should then show in the Online system that we use. We may need you to change the Invoice template slightly on our whmcs system.