Restricting Tcode using Roles

Dear BW Experts,

I want to create a role to restrict of accessing TCODE : STMS_IMPORT and STMS in Production system. I can able to create a role by adding S_TCODE. While creating the role, inclusion is available but exclution is not available. I want to create a role by restricting tcode STMS and STMS_import. How to achieve this. Please help.

Thanks.