Change 'date created' attribute using the filename

Bit of an odd one.

I have just converted all my video files to be Gallery 3 compliant (mp4) but during the process the time stamps got wiped. Luckily all the files were named with the date and time taken.

I have found lots of software (windows) to create the file name from the date taken but none that will do this the other way round.

Just to add to the complexity it needs to be a batch job due to the amount of files.

So something that can read the file name and then populate the time fields of the file.

Any ideas.