User Restrictions

hai,
i am a VB devekoper, and now working on a SQL Query Engine.... the appn. will QUERY the SQL Server(SQL)...i made the appn. to create a USER (say: QueryEngine), and i log in with the same UserName... now i want to set some restrictions for the User(QueryEngine) to provide READ-ONLY access, and that also through some SQL statements, so that i can quey the Server each time the appn is opened...
i tried out the "GRANT" sql key word but it didn;t work oput...

anybody has any solutions

expecting the reply ASAP

regards,
abhay

User needs proper permission to execute grant statement.