Tweaking VSCode Platform plugin to highlight evaluated code

Hello all,

In VSCode Platform I would like to highlight the background color of a selected text that was just sent to REPL.

I was thinking about this by updating vscode-ocaml-platform/src/repl.ml at master · ocamllabs/vscode-ocaml-platform · GitHub , but I have no idea what to do next. Can anyone give hints for me?

Thanks,