Watch this Author's files
Didn't fully test for empty field cases like some commenters but I got a nice structure out of my input file.
I am disappointed that a similar functionality isn't built in Matlab. xmlread and xmlwrite alone are such a pain to access and/or update xml data.
I have now tested this submission all the way up to R2013a. It works. The warnings people are talking about are just that "warnings". It still works.
Other than cluttering up the command window or the DOS window for the stand alone executables, functionally I have no issues.
Though I would agree that someone should generate up to date .p files but then I am not sure if it would make it unusable for people with earlier versions of Matlab.
If the author doesn't mind sharing the source code, that would solve the problem too.
Of course, best possible solution is for Matlab to include this functionality with built-in functions.