Without the source your only hope is to use the mechanisms left by the developer. If there is no ActiveX and the only interaction is with a mouse and keyboard, then you'll have to simulate a mouse and keyboard. There are several examples of using AutoIt or LabVIEW to look for windows to be active (based on their titles) then simulate pressing keys to navigate where you want and type in information. This is quite error prone and user interaction may mess with stuff.