SQL Security :: Giving Access To A User Using DOS-Batch Script

Is it possible for a batch command to give access or add a new role for the user to database? Basically:

USE my_Database
CREATE USER [User1] FOR LOGIN [User1] WITH DEFAULT_SCHEMA=
[dbo];
EXEC sp_addrolemember 'Application1', 'User1'
EXEC sp_addrolemember 'SQL_Read_Only', 'User1'

If User1 was already created then ignore that and run the exec sp_addrolemember. Next, 

EXEC sys.sp_change_users_login
@Action = 'Update_One',
@UserNamePattern = 'User1',
@LoginName = 'User1',
@Password = NULL

to link the orphan user within database.