"Convert" the content of a page into xml

"Convert" the content of a page into xml

I need to generate an xml page starting from a simple Wordpress page. I have the code and I am able to generate the xml, but I don't know how to format it as I like.
My source page is something like this:
<h1>Useless title</h1>
<p>HH:MM Name1</p>
<p>HH:MM Name2</p>
...
<p>HH:MM NameX</p>
and I need an output like this:
<mytag>Name1</mytag>
<hour>HH:MM</hour>
<mytag>Name2</mytag>
<hour>HH:MM</hour>
...
<mytag>NameX</mytag>
<hour>HH:MM</hour>
Is there a way to do this?
Thanks, have a nice day!