You would step through each character in a string (the whole or part of the
XML file) and compare each character "<"

when you found it you would then continue to step through the string comparing
each character with ">", other characters would be added to a string variable.

When you hit the ">" You would (either in the process or subsequently) test
the content of the string variable to see if it represented a valid numerical
value.

Then you would make the value of the relevant cell in your spreadsheet equal
to either the numeric value (using cLng or a similar casting function) or the
string value directly.