Using SQL code with excel power pivot

I'm using SQL code (which I do not know, I just tried to copy from a sample tutorial) to merge documents to use in Excel PowerPivot. I have an excel file called 2014, and another file called 2015. This was the syntax shown in the example to merge the two, but it keeps telling me columns not identified. How can I fix this?

SELECT ['2015$'].*  FROM ['2015$']
UNION ALL 
SELECT * FROM 'C:Alex2014.xlsx'.['2014$'];