HELP - PHYLIP dataset too large for Excel!!

[MERC]

    I am trying to use RESTML on 37 taxa with 6 enzymes and about 600
fragments.  I currently have each enzyme's data in Excel separately.
This dataset, though, is too large to combine into one Excel file.  How
can I put all of this data into one file so I can run RESTML?
Thanks,
Emily Latch
Cedar Crest College
100 College Dr. Box #244
Allentown, PA 18104-6196
Phone: (610) 606-4968
Fax: (610)606-4616
Email: merc at cedarcrest.edu