String to Numeric conversion in csv file

Hi All,

I want to perform analytics on a series of excel files( 30 files with same format). I took them as input and converted them into one large CSV file. 

In the CSV file, I have a column 'A' which were stored as strings in their excel format when they actually were Numeric. 

I want to now convert this column 'A' from string to numeric in the CSV file but am not able to do so with either the ToNumber([A]) fuction in the formula tool or by changing the Filetype in the Select tool.

Please advise .