Syntax Error - OUTFILE with Timestamp
The immediate issue is that you are appending the formatted date string and .csv' to the end of the query string, rather than to the end of the file path as I am assuming is the intention.

It seems to me your CONCAT expression should actually go like this:

CONCAT("SELECT ... INTO OUTFILE 'E:/Data/exports/DailyExport/myfilename_"
  , DATE_FORMAT( NOW(), '%Y%m%d')
  , ".csv'
    FIELDS TERMINATED BY ','
    ..."
)


Note that there's no ' at the end of the E:/Data/exports/DailyExport/myfilename_, because the date is appended at that point, followed by .csv' which completes the name.

Once you have fixed that, you are going to face another issue, which will be caused by the ENCLOSED BY line of your dynamic query. The ' character must be escaped when itself enclosed in '. So, it should be either:

...
ENCLOSED BY ''''
...


or

...
ENCLOSED BY '\''
...