Dynamic method invocation based on URL Param

Question

I want to hit a URL such as /mysite/test?do_this?execution_method

I want this to take me to the action method execution_method()

via the following struts.xml action

<action
    name="/mysite/test"
    class="com.app.test"
    method="{do_this}">
        <result name="success">/success.jsp</result>
    <result name="failure">/failure.jsp</result>
</action>

I know the above doesn't work, but how do we get the URL query param to be executed?