This is not *Necessarily* difficult, but it is a bit clunky... Feel free to reach out to me directly if you'd like to chat about it...
It will be easiest to have a separate SimplWindows program running in another processor for your integration. Here's what I would do:
1. Plan to have your integration recall scenes or buttons (ex: toggles for Load Control) for each room
2. Set up/Program a 'Virtual Keypad' for each room - Add a 'Virtual CNX-B12' to each room which will give you 12 buttons and LED Feedback for each room.
----- You can duplicate functions that are on actual keypads in each room or just some basic control for integration.
3. In the OTHER DEVICES section, add a Remote System Export (Named Virtual Keypads) and Add ONLY the Virtual keypads in each room, to the 'Export Devices' tab, Then in the 'I/O Assignment' Tab, set an IP-ID and the IP address of the SimplWindows processor.
4. On the FINISH section, build your system again. This will create an RSD File that you'll now import into your SimplWindows program
5. On the SMW side (SimplWindows), Import the RSD (Project/Import Remote System Definition), which will come in as an EISC. Make sure you hit F6 and set the IP address of the Pac2 and verify that the IP-ID is the same on both sides.
6. The imported RSD in SMW will now give you 'human-readable' names that you set for the Commands and Feedback for each of your rooms, and you can program triggers to them from anything in logic...
7. RTI - You're on your own on this part!? But, I'm quite sure that you can create in the RTI interface some sort of RS232 or IP driver with simple commands that it can be sent (ex: Preset 1, Preset 2 or MBed-Toggle, Dining-Medium)
8. Use an SIO to receive the incoming strings from the RTI interface (Serial or IP) and attach the command triggers to the appropriate commands on the virtual Keypad RSD.
Obviously, there are tweeks and logic details to manage and flush out, but this is the basic framework that you'll want to work with...
HTH!