Best way to automate FileMaker data import  when I only have the option of .tab or xls.

I am downloading (daily) a file from an external Website where customer credit info. is stored and updated.  The only option they offer for extracting the data is in excel fomat, or tab.  This is the method I use currently:

Save as Excel file named content.xls (I do this b/c I have to change formatting)

Open another Excel file named ~Main, which uses the content file as a datasource to automatically pull data from the latest download.

Then, FileMaker uses the "~Main" file to import the data via an ODBC relationship.  

The reason I am asking the is because I don't have much experience setting up auto-updates with sources outside of FileMaker, and this is just the 1st of many I would like to automate.  I am farily sure I am making this more difficult than it needs to be, AND adding too many steps; however, this is the best way I know to handle this with my limited knowledge!  I also need to set up similar relationships with data extracted from SAP, so I am really looking for good advice on the most efficient way to set these up--the RIGHT way.  A problem I am having now with the way I am using the xls/ODBC setup is that I cannot seem to get the dates to format right in Excel...automatically anyway.  So, they (of course) import into FileMaker in a skewed form. Thanks for your help in advance!