@Angela-Tovar
this question is, should it be a real excel spreadsheet or a file which can be imported into excel.
If the latter is the case then make sure that your file has a header and the rows
do e.g. use , or ; as delimiter.
header and rows must have the same number of fields
So something like
header1;header2;header3;…
value1;value2;value3;…
Cheers
Claudia