Is there a way to use wildcards in the command line?

e.g. cp /system/wallpapers/*.lua /appdata/system/wallpapers/

Couldn't you just copy the entire directory instead?

I gave that a shot and it overwrote the folder that was already there, unfortunately ... not a bad thought, though. I was hoping it would merge the two.

An entire copy of the directory is losing out on the value of wildcards in the first place. Use cases are certainly more limited in picospace but could still have value for sure.
I found /system/apps/terminal.lua which seems to handle all of that and I can't see any mention of wildcards a feature there.