Hi, I have my own domain registered with 1and1.com. And I have already point my domain's dns to ns*.dynu.com.

After referring to https://www.dynu.com/en-US/Forum/ViewTopic/How-to-create-CNAME-to-Heroku/3372 and https://www.dynu.com/en-US/Forum/ViewTopic/Own-domain/240, I am still not quite sure how to achieve my targets.

Ideally, given my domain is "test.com", my account at dynu.com is "myaccount", all the below domains shall point to my home server:
1. test.com
2. www.test.com
3. myaccount.dynu.com

Thanks for your help!

Sign up for DDNS service for test.com and myaccount.dynu.com at https://www.dynu.com/en-US/ControlPanel/AddDDNS and change name servers for test.com to Dynu name servers. The instructions at https://www.dynu.com/en-US/Forum/ViewTopic/Own-domain/240 are quite clear.