I asked about what the intended use of such a utility would be and based on a couple keywords ("view and verify before they send") you basically want to do the following:
- Make sure the file is in standard format with the right number of columns (and rows, maybe)
- Give some stats like total number of records, total number of items sold, date range represented in file, etc, etc.
- Save the file to either a central server or to a waiting area for upload later.
The right way to accomplish this, in my opinion, (especially because, as you say, many customers still have mainframes and still get data in formats like this) is to use a custom front-end to get the information about the data to your customer.
The way to do that? You have essentially 2 options: either a) write a file-parser yourself in Java, C#, or C++ (shudder) to give a 'preview' of the data contained in the files. Or b) hire a member or recent graduate (check a portfolio first!) of computer programming classes to code a parser for you. Or the boss' nephew, or your sister's nerdy boyfriend, etc. I don't know what experience or interest you have in such a thing, nor anything about your background, so please forgive me if I'm making undue assumptions. As with so many other things in the world of Technology, you can have any two of fast, cheap, and good.
The lowest cost and fastest option of those presented so far, which span the range of possibilities I'm aware of as a technology professional, would be to bite the bullet, learn some vim (use GVim for Windows) and use syntax highlighting filters there. Second would be to make a series of scripts in something like sed or awk.
Since the input to your problem is essentially a stream of text chopped off at intervals (the line breaks) the processing of the data has to handle input in the same way, and very few programs do so now, because, as you say, this is data generated by an old mainframe program.
Excel might also be of use in importing, but all the lines have to be formatted the same way, so that's still not going to do what you want. One additional thing that comes to mind is that you might be able to use Access to parse such a file and use some VBA to create record counts and compile statistics, but as far as overlaying highlights, that would be less easy. If you know any COBOL developers, this would be a great 1-2 night project for one of them. It might even turn into an open source project on sourceforge.net to free data from the clutches of the mainframe!