force new edge beta to run in sbie

my problem is is with the new edge beta which is based on chromium, but is not chrome. i am running it on win 7 and 8.1. i can't figure out how to force it to run in sbie. if i rt clk and select run sandboxed it does, but with it set as my default browser, when i click links it opens un-sandboxed. new edge beta does not appear in the default box settings list of browsers so how do i add it to be forced?