u/AlpiePEAKS

In summary, I want to have a command block which executes a command.

This command would have the location of execution be positioned on a certain point. Afterwards, it would ideally check for players within 16 blocks of it and then summon an armor stand (or mob) by a player within 16 blocks of it.

Any thoughts?

This is how far I got:

execute at @a[distance=..16,gamemode=adventure] positioned -20 -33 -29 run summon armor_stand ~ ~ ~ {Invulnerable:1b,Tags:["target"]}