How do I use str_to_date in a batch correctly?

Question

I am using a batch to import csv files with a scheduled task. My batch is as follows:

C:\xampp\mysql\bin\mysqlimport.exe --host=localhost --user=FAKEUSER 
    --password=FAKEPASSWORD --delete --fields-terminated-by="," 
    --ignore-lines=1 --fields-enclosed-by="'" --fields-escaped-by="'"
    --lines-terminated-by="\r\n" insurance C:\import\ins_employees.csv 

The csv I am importing contains hiring dates, leave of absence dates, etc.

How do I use the str_to_date command in my batch so that it will convert the date fields (mm/dd/yyyy) to the proper SQL format?