To boil this down to a simpler question, you want to remotely control your MacBook's screen from your Windows laptop.
You will need to use a VNC Client to remotely control your other machine from another system. Doing a Google search on how to use VNC software should resolve your quest to do this. This is not anything PreSonus support can assist with as this is more of an IT utility used by network administrators to control computers.
A router is recommended, if you don't want to use one, conceivably if you setup your MacBook and your PC as Static IP's using your wired connections you could do this, however you would lose wireless connectivity on your Mac as it always defaults to wireless. If you're not sure what I'm talking about, contact an IT professional to assist you with this. IT Administrators use VNC clients all the time to control servers.
