How to create dictionary limit from 8 - 12 character

[dtthhoanglong]

Hi, everyone. I want create a dictionary for method dictionary attack. But i don't know. How to create custom dictionary. Example i have some key: "dung, phuong, thao". I want create a dictionary combine from list key there with number and character as "@", and it limit from 8 - 12 character. How can i create it ? 

Example: dung1234, dungthao12@@, phuong124,thaodung44@