Ahhh.. sorry, I misunderstood the quesiton...
You could use execute to build the select string and execute the string as in:
USE PUBS
GO
DECLARE @sql_str varchar(255)
SET @pID='A015' -- cant start with a number, so I made it start with a char.
Set @sql_str = 'SELECT au_lname AS ' + convert(varchar(30), @pID) + ' FROM authors'
execute(@sql_str)
But note, however, that an alias cannot start with a number, it must start with an alphabetic character.
Thanks,
Tom