I think you roughly got it.

Easiest way is to work with STRINGs

str_cpy and the like can copy char arrays into STRINGs, or STRINGs into STRINGs, but not char arrays into char arrays.

For using native C strcpy which can do the later thing (and nothing else) you should be able to find examples in the Contributions forum. People have added these functions before - it should just be a copy&paste issue. But probably they are already available by default in the latest lite-C release. I've only tested with a rather old version.