Currently, no - and that is for security reasons. You'd not want for users to have access through JS on sensible datapoints without going through the proper process (for auditing purposes).
But you can do it by invoking the java classes on ScadaBR. Java classes are accessible from the JS execution context. There are some example here in the forum on how to instantiate and use them, but you'll need some knowledge on the Java classes and architecture.
ScadaLTS has set a sandbox to avoid this behavior, also to improve security.
What I'd recommend is - use the proper UI components - or - develop your components to ensure a balance of security and function.
Hope this helps