<p>I have been given a set of COBOL DAT, IDX and KEY files and I need to read the data in them and export it into Access, XLS, CSV, etc. I do not know the version, vendor of the COBOL code as I only have the windows executable that created the files.</p>

<p>I have tried Easysoft and Parkway ODBC drivers but I have not been successful in reading the data from the files.</p>

<p>I do not have access to the source code as the company that was distributing this product shut down.</p>

A few possibilities.
1/ See if you can find the names of the people that worked for the company.  They may be helpful.
2/ Open the DAT file in a text editor.  The data may be decodable from that.  If the basic format can be discerned, quick'n'dirty code can be written to extract it.
3/ Open up the executable in an editor, there may be strings in there that indicate which compiler was used, then you can search for info on its file formats.  If it's a DOS application, there's a good chance it was either Microsoft or Fujitsu COBOL.
4/ Consider placing job requests on work sites like elance or rentacoder; I don't think there's a cost if the work can't be done successfully.
5/ Hire someone to examine it and advise on the likelihood of recovery.
6/ Get a screen dump of the record contents for every active record and re-construct it from that.
Some of these are pretty hard so your mileage may vary.
Good luck.