Okay, I think I see now. You want to click the game's Action Bar buttons with the mouse. That wasn't exactly clear!

If you don't need it to auto-assist when you click -- you can manually assist with the "FTL Assist Me" hotkey anyway -- then one easy way to get what you're asking for is with a
Repeater Region. This sets up an area (like your Action Bar) to automatically broadcast the mouse to whatever windows you want.
To set up a Repeater Region for this:1. In the game, press Ctrl+Shift+Alt+G to bring up the in-game
ISBoxer Control Panel2. In the ISBoxer Control Panel window, select the "repeater regions" tab
3. In the Target drop-down box, select the option that matches the windows you want to send to. If you want every window to click when you click on an Action bar button, pick "all other" -- the current window will get click because you will not enable the option to block it
4. Click "Add" next to the drop-down box; your new Repeater Region appears.
5. Move and size your Repeater Region over your Action Bar
6. If you would like an identical Repeater Region in every window -- because you want to broadcast FROM every window just like from this one -- then click the Sync button to clone it to all windows
7. Click "Save As" in the ISBoxer Control Panel window, with the box left as "Auto". The "Auto" regions will load by default whenever you launch or reset your team.
You may want to change the FTL Assist Me hotkey to be something more convenient than Alt+Backspace. For example, you could make it Alt+Mouse3 or something and then if you hold Alt and click your mouse's scroll wheel they will /assist you.
To change the Assist hotkey:1. In ISBoxer, in the top left pane, under Key Maps, select General
2. In the bottom left pane, under Mapped Keys, select FTL Assist Me
3. In the bottom right pane, the top option is Hotkey. click the < to change it
4. Export to Inner Space after making any changes in order to activate them!