Use the file browser to select the ASCII file on your hard drive and click on "Open." Click on "Next" once the Import Text wizard appears on your screen. Select "Delimited." ...

option from the File menu, select the columns to export and then choose either "comma separated text file", "tab delimited file" or "fixed width text file" from the "Save as type" dropdown.

You'll need to process the file using some other tool to get any useful information. If it IS the BAM I'm thinking of, it's actually probably a SAM file, which is the human-readable, tab-delimited ...