Have a look at this post:
My custom keyword HighlightElement magically extends the built-in keywords such as WebUI.click(), WebUI.setText(), WebUI.selectOptionByValue() so that these keywords give highlight to the HTML node while keeping their own base function (clicking the node, setting a text into <input> node, etc) unchanged.
You want to develop your own custom keyword which extends the built-in keywords of your choice so that they do something additive while the original function retained. Please study the source code.