Editing VBA code in other workbooks using VBA code

Hi,

I'm looking to essentially find and replace some text in VBA codes in various workbooks. My intention was to move all the workbooks to a certain folder, then have an editing code which basically says:
- for each workbook in folder XXX
- for each element of code in each workbook
- find "123" and replace with "ABC"

I've never done anything involving changing VBA code using VBA code, but I assume it's possible as I've googled some terms but can't make sense of it.

I'd appreciate any help/guidance!

http://www.cpearson.com/excel/vbe.aspx