Upper-case for the Second Character

Hello, could some one please help with the following:

In column J of my Excel 2003 worksheet named: Sheet1, is a list of mailing addresses.

A copy of the spreadsheet is attached.

I need a macro to please capitalise (Upper-case) the second character only of all the Post Office addresses.

Example:

Po Box 65, ORLANDO, NSW 2697

All of my Post Office addresses are prefixed: Po

I need the Post Office addresses to be prefixed: PO

So, the above mentioned example should look like this: PO Box 65, ORLANDO, NSW 2697

If any one could please help - that would be much appreciated.

Kind regards,

Chris