That's a neat technique, thanks for posting.
Quite a common requirement seems to be reading the first n characters, or the first row, of a text file to determine its type/layout before directing to the appropriate dataflow - I reckon you're well on the way to cracking that with this.
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.