Autopopulate the main field of any module

Autopopulate the main field of any module

There are certain module such as deals where we cannot add a function in the main deal name. Is it possible that I can make a deal name as a compilation of different variables in the deal like "Customer Name-Quantity-Quality". Can you help me with the code?
And I have gone through various autopopulate questions but in each one of them the field is filled up after the record is saved. Is it possible that while I am entering a new field automatically the field autopopulate like in deal when I fill the customer name, company name gets filled automatically