Power BI advaced query Editor

good morning

I am searching if it possible to use variables, in the advanced query editor, something like this:

instead of:

------------

let
Origine = Sql.Database("99.99.99.99", "Mydb", [Query="select data from mytab where code = 66....

in

Origine

something like this:

---------------------

let variab = 66;

let
Origine = Sql.Database("99.99.99.99", "Mydb", [Query="select data from mytab where code = variab .....

in

Origine

or any doc about ...

 thanks