AutoFill from the Left

Dear All,

Thank you for taking the time to read this.

In my Query I've this kind of Data

Type1   Type2   Type3     NEW COL
AA         BB                         BB
CC         DD         EE            EE

I would like to add a new column that does the follwing:

(if type3 ="" then (if type 2 ="" then type 1 else type 2) else type 3)

the reason is that I want to map and merge with another table 

Mapping Table
BB   BALI-BALO
EE    ELI-ELO

Is this possible ?

Regards,

Laurent