Query tool - How to get data from custom fields

Hello everyone,

I am running a Query to get some info about a item.

Table ITMMASTER; Field ITMREF; Others Fields by default.

The info that i need is related with a Custom Field, where i need the value of the field and their descripton. 

Table ITMMASTER; Field YACAB; Others Fields by default. Will return "V02", How do i get "VZ MT"? 

I already try collect the descripton from the tables ATABDIV and ATEXTRA but i do not know how to make the connection. 

Someone can help me?

Thank you guys.