How to create a synonym for a column in SQL Server?
If you want to retain the table name but refer to an existing column by a new name a computed column will do this for you. The computed value of the column will be just the value of the existing column.

alter table [dbo].[Product]
add [ProductTest] as ([ProductId]);


Now you can write

select
    [ProductId],
    [ProductTest] 
from [dbo].[Product];


The two columns will have the same value, always.

If you reference only the computed column my guess is there won't even be a run-time overhead.