Associate url to a class that extends action class

i want to associate url to a class that extends Action class(struts).i go on sturts-config.xml file and i write the following lines:

<action path="/threed1" type="DManager1" validate="false">
<action path="/threed2" type="DManager2" validate="false">

and tomcat create instances of DManager1, DManager2 and associate these instances to paths /threed1, /threed2.

in fact DManager1, DManager2 are the same class.

what i want to do is to create dynamically two instances of DManager and associate paths to these instances without write these lines on sturts-config.xml file

i need a dynamic way to do it.