Use the Read function to play a message and accept the dtmf into a variable. You could use DBPut and DBGet, but I'd recommend an external database like MySQL to store the values. You'll need to write an external program (PHP, PERL, etc.) to read from the records you stored in the database and send the calls out via AMI or call files. You'll probably also want a separate context to handle these calls. Use the crontab to schedule the program to run. I also use the AMD function to check if a human or machine answered.