Alt Space U

Hi everyone ! I'd like to create a Windows shortcut for my Basilik mouse with Synapse, and I'd like this shortcut to execute "Alt Space U" when I click on a mouse button (to minimize the active window to the taskbar). The thing is, it seems that I can only assign a series of 2 keyboard keys, not 3, to a mouse button :frown_: Any idea how I could work around that ? Thanks a lot