Programming Replication using T-SQL Stored Procedure

DECLARE @publicationDB AS sysname;
DECLARE @publication AS sysname;
DECLARE @login AS sysname;
DECLARE @password AS sysname;
SET @publicationDB = N'cccsql'; 
SET @publication = N'cccsqlMerge'; 
SET @login = $(Login);
SET @password = $(Password);

-- Enable merge replication on the publication database.
USE master
EXEC sp_replicationdboption 
  @dbname = @publicationDB, 
  @optname=N'merge publish',
  @value = N'true';

-- Create new merge publication, using the defaults. 
USE [cccsql]
EXEC sp_addmergepublication 
  @publication = @publication, 
  @description = N'Merge publication.';

-- Create a new snapshot job for the publication, using the defaults.
EXEC sp_addpublication_snapshot 
  @publication = @publication,
  @job_login = @login,
  @job_password = @password;

-- Start the Snapshot Agent job.
EXEC sp_startpublication_snapshot @publication = @publication;
GO

Highlighted in bold how do I write/set the Login and password if using SQL Server Authentication..?

Thank you

R