DoB to ID number

We have a number of folders that have been created with a particular naming convention: Initials, Date of Birth, Practice Area, Date of aquisition of Data - for example TT020953STA251112 - in that folder there are subsequent sub-folders with file names that include that string in the name e.g. TT020953STA251112_03-12-12.txt. There are also XML files that contain the string within the content of the file. We now find we need to change this naming convention to a simpler one based on the person's ID number e.g. 4100245 We are looking for a programme that allows us to change all instances of the original string to the new ID; it may be done in a script format referencing an Excel or text file containing the original names and new IDs, or a programme that allows a user to pick the original folder and new ID and submit the request to make the change. Or any other method you feel more appropriate. There are approximately 2000 records to change.