Let's say that:
I cast Glyph of Warding and imbue Crown of Madness into it, with the trigger being a creature in a party of 2 or greater steps on the glyph.
A party of 2 walks over the glyph and the first creature triggers the glyph.
The creature fails his Wisdom saving throw.
I, the caster, am nowhere near the glyph, meaning I have no sight of the creatures and no way to know the glyph has been triggered.
A. Can I still mentally choose a target for the creature to attack?
B. Can I make him attack his buddy?