Proper Indexing stategy

All,

I have a table that has a surrogate key (means nothing) and then 4 additional columns that represent the unique record.

I was thinking I should do this:

Create a primary key on the surrogate key only.
Create a unique key on the 4 additional columns that make the unique record.

Queries will be querying the additional 4 columns, they will never query the surrogate key.

What is your opinion.
Thanks,
Kathy