Hi,
I have build these kind of auto dialers many a times , you can find a few in my freelancer profile as well,
https://www.freelancer.com/projects/Asterisk-PBX/generate-phone-calls-specific-numbers/
https://www.freelancer.com/projects/Linux/Build-calling-system/
I need to know a little more about your project,
kindly let me know if we can discuss it over chat,
regards,