Batch rename files

[Arcady Genkin <a.genkin@utoronto.ca>]

What would be the easiest way to rename a bunch of files

foo-[0-9]-bar-[0-9][0-9].txt

into

blah-[0-9]-[0-9][0-9].txt

Note, that all of the files have identical portions `foo-', `-bar-',
and `.txt' in the filenames. Different are two numerical parts.

For example:
,----
| group-1-member-01.txt
| group-1-member-02.txt
| ...
| group-2-member-01.txt
| ...
`----

The resulting files should have an identical portion `blah', and
retain the original numerical parts.

,----
| result-1-01.txt
| result-1-02.txt
| ...
| result-2-01.txt
| ...
`----

Thanks for any suggestions!
-- 
Arcady Genkin                                 http://www.thpoon.com
Nostalgia isn't what it used to be.