client server communications vb6

Hi I have a client server application that was developed in vb6 but the communications was not built in so all updates were via memory sticks. I have now be dumped with making this work via the internet / WIFI so that updates both ways are real time. The system on the tablets (clients) is a vb6 applications that formats and displays screens for the user to complete and then is updated to the server for verification and subsequent download to the tablet (clients). The system on the server is a vb6 application that takes the input from the tablets (clients) verifies and update to a SQL database. If successful it then formats the next details for the tablet (client) and downloads it with a success flag set to YES. If unsuccessful it just returns the details with the success flag set to NO. The requirement is to supply routines, and their code, to achieve this via the internet and / or WIFI. The routines must include the logon to the transport method as there will be instances where no Internet ot WIFI is available and this must respond with the success flag set to NO with a message detailing the problem. The details being sent both ways will be a delimited character string. Your suggestions on how to achieve this, at what cost and in what timeframe. Regards Mac