DSXchange

Yes, you can do this in DataStage. This assumes you use a Sequence to get the filename or list of filenames and then you can process this to extract the date.

p.s. Please don't use ASAP in a post, it usually will cause any answers to be much slower. ASAP and URGENT are for paid services and usually carry quite a premium

If the file name is a job parameter you can make this test in a simple expression if all you want to test for is "contains eight contiguous digits". If you want to check that they form a valid date then you will need a Routine.