If the DAT file you're trying to open is text, you can convert the file into text in the Microsoft Excel program by first saving it as a CSV file.

Learn how to import or export data from a Text file to convert a Text (.txt or .csv) file into an Excel (.xlsx) spreadsheet easily using this procedure.

Using the Excel Text to Column feature, you can choose how to split the column up, fix the width, or split at each comma, period, or other characters.

Converting texts between formats is a bit of a pain to do on a file-by-file basis, but thankfully, MacIssues shows how to convert text files in bulk using a simple terminal command. The tool you ...