File Parsing and Editing Help

[Matt Picone]

Barians,

I am working on a software project (music related!) which involves an 
XML file and I lack the knowledge of regular expressions I need to 
modify it easily.

What I have to do is identify all instances of a certain construction in 
the text and change the case of certain characters.

The construction always begins with "item", is then followed by a 1-3 
digit number (1, 11, 111), followed by an equal sign, quotation marks, 
some STRING VALUE, and then the close quotes.

I want to change the VALUE from ALL CAPS to INITIAL CAPS, unless it is 
found on an exceptions list (USA, ms, Hz, etc.)

What do you recommend I use to make this change throught the file? I 
need to do it easily and repeatedly over time.

RegEx? PERL? Something else? Any tips pointers, or outright assistance 
will be blatantly rewarded.

Thanks

-m@