My apolgies, I was going more for a simple "Replace Text" approach, but your way is better, so:
Read from Excel
For each row in Excel
Read XML from file
Set XML element value
Set XML element value
Set XML element value (as many as columns you have)
Write XML to file (write to a different file, don't mess up your template)
End for each
For Set XML element value, mine looks a little difficult, cuz my XPath got messed up by some garbage that was in the way of the normal path:

But there are tools to find your XPath query, or GPT should be able to help get this right. If you have the paid GPT version, I have a PAD Assistant GPT that I made that might be able to help you.
Regards,
Mike