If I understand correctly, you have a file called wrongdatefile20140228.csv and you need to create a new file called correct_date20140228.csv? Assuming bash shell:
$ ls *.csv
wrongdatefile20140228.csv
Assign filename to variable $fn and use Parameter Expansion
$ fn=wrongdatefile20140228.csv
$ awk '...' "$fn" > "${fn/#wrongdatefile/correct_date}"
Result:
$ ls *.csv
correct_date20140228.csv wrongdatefile20140228.csv
To automate this for all files wrongdatefile*.csv in current directory, skipping previously processed files:
for fn in wrongdatefile*.csv; do
newfn="${fn/#wrongdatefile/correct_date}"
[ -e "$newfn" ] || awk '...' "$fn" > "$newfn"
done