Read Office Excel files from the Azure application


We have a requirement to read an excel sheet from the Azure worker role. I understand that we can do this using Open XML SDK. It seems we cannot use Interop assemblies (correct me if I am wrong). We need to able to read ALL version of excel (2003 and older). Any pointers will be appreciated.

I think NPOI is available for the case, because NPOI can read old excels(but I have never tried in practice).
This is a link of NPOI

And Open XML SDK can not read the excel (2003 and older).