OFX Glow Mask

Just started playing with the OFX Sapphire plugins for Flame.
In the Glow, I was looking to try to use it like the old Glow Mask, but can not figure out how to use an alpha as a mask?

Whenever the question is “how do I add a mask…” or “it would be nice to have X effect added to Y effect”, my answer is always: have you tried Builder (S_Effect)? In there you can add a mask to effects that don’t have a mask input and much, much more.