Changing File Names in Excel Folder

snb: It worked! Thanks to everyone for their help! It was very instructional, very helpful, and most appreciated!!!
JPDutch

I'm wondering if someone could help me figure out how to write a macro that will allow me to change all file names in one folder (I'd like to change the year). The path is as follows:

H:\SAFETY\FORMS\ 300 & 300A\2011

The files look like this:

Branch 007_2010
Branch 008_2010
Branch 009_2010
Branch 010_2010

I'd like to change the files to this:

Branch 007_2011
Branch 008_2011
Branch 009_2011
Branch 010_2011

Any advice you could give me would be appreciated!