Currently I'm importing .ass files into LOP this way.

Your text to link here... [forums.autodesk.com]

And then I want to edit intensity and exposure values like set parameter node in ROP.
Does anyone have any ideas?

You can't edit anything since it's loaded as a procedural.

jsmack
You can't edit anything since it's loaded as a procedural.

Oh I see.
Is it possible to edit around it somehow?

Im not an absolute TOP savvy nor use arnold much, but that should be well possible with a python node.
If you have your file path accessible via attribute or similar, you could open it and use regex to edit the file as u need.

Operators are cool, but not supported :/

From the help [help.autodesk.com] page.

"Known limitations
Operators, environment shaders and camera shaders are not currently supported."