To access it I hit F2 and select my script which works.
Example

but if my path has ! at the start of a folder name it fails.
Example

How can I delimit the ! in lua for my real path?
I assume you mean “escape” rather than “delimit”. It's not Lua that makes the difference, it's the User Menu,
!
is a special character there. I encourage you to read the built-in Help on this (press F1
while the menu is open and then activate the (very first) Special symbols
hypertext link by hitting Enter
).I did mean escape but couldn't find the edit option.