Importing Excel xlsx into Xcelsius

Hi

Just a question on importing excel file.

Xcelsius allow us to import xlsx (2007-2010 Excel file) but only limits to xls format once its imported to Xcelsius.

I have an xlsx excel file which contains 700+ columns, and once imported to Xcelsius it cuts it back to 256 columns.

Is there anyway to keep my xlsx format in Xcelsius?

Thanks in advance