Hey There
Im am not to sure about the process of pulling the data out of an excel file unless it is in a certain format such as a csv etc
By placing the data within SharePoint however this task becomes very simple. Instead of the data being held within the Excel file, you would instead create a "Custom List" and recreate your fields(columns). Then you can use datasheet view to enter and edit your data, just like Excel.
As far as then taking this data out of SharePoint and into InfoPath, what you would need to do is create an XML data connection which looks at the GUID code (which you create from the URL fo your list).
Once this is done, a few lines of C# and you can filter your data to your hearts content.
The process sounds a bit scary, but trust me it is easy.
If that sounds like what you are looking for, I would be very happy to send you some links to walkthroughs, and give you some help.
Regards
Ryan