data manipulation

[Jeff]

The function expects an excel file.  It cannot read a plain text
file.  You would need to figure out a way to convert the text file
data into an excel format and save it to a new file first.

The proper way to handle this is to make your data processing
functions expect a defined format.  Then, you write importer functions
for various types of files that convert the data in each file to the
defined format.  That way, you can support various file formats and
reuse your processing functions on all of them.