It's best to provide context when asking questions, because the answer depends on what your overall end goal is.
If you need to do this for lots of functions, the best approach is probably to make a Cordova plugin, and a Construct plugin that talks to the Cordova plugin.
If you only need to call one function and just want a quick shortcut, you can call functions from JavaScript. So you just need a way to make the WebView run that JavaScript. The WebView class should have a method for running JavaScript.