Boros Battleshaper's ability reads
At the beginning of each combat, up to one target creature attacks or blocks this combat if able and up to one target creature can't attack or block this combat.
My opponent and I each have a Boros Battleshaper, and my opponent is attacking. If she targets one of my other creatures to prevent it from blocking, can I use my Battleshaper’s ability to ‘force’ the effected creature to block?