when it comes expressions, i'm completely useles. I've no idea what you mean. Clicking on a button would make it so easy, and as such there would be no need for expressions.
Might be best to avoid specifying an *implementation* (eg. a button), and let others help you find the answer to the problem you want to solve.
The answer is already built in, and is more generalized so that it solves more problems (like yours). Your case is just one in countless other possible I-need-a-button scenarios.
See these, as to how easy it is to remove the text you don't care for, or even more generally, add what you want. You currently have the first situation, but desire the third. Others have mentioned how to change the text that appears in your view. I'll show you one example. (Your "button" turns into just clicking on the pulldown menus).