Referencing an Endpoint?

Hello, I am a complete novice to automation and soapUI. (Today is my first time using it). I also have not touched any sort of scripting/programming in over 7 years, so please excuse my mistakes.

I am verifying the existance of some XML node. When the nodes don't have a namespace, such as:

<node1>
      <node2>

I can easily use xpath:

exists(//node1)

or

exists(//node1/node2)

When there is a namespace, which can change, I am not sure how to handle it. I was thinking of doing a wildcard, but the following did not work:

declare namespace ns1='http://endpoint/dir1/dir2';
exists( //ns1:node1)

to

declare namespace ns1= '*';
exists( //ns1:node1)

After that did not work, I found that I could just ignore the namespace entirely by doing the following:

exists( //*[local-name()='node1'])

However, now I think I want to somehow reference the endpoint so that whenever I use different endpoints, I can verify the endpoint.

So, if my endpoint is http://endpoint:8080, how would I have done the previous by referencing this?

Lastly, if I can somehow reference the endpoint, how would I add the rest of the URI to the base endpoint, given that the rest never changes. Only the base endpoint does.

I would imagine it would be something like

declare namespace ns1=myEndpoint + "/dir1/dir2";
exists( //ns1:node1)

Thanks in advanced.