Security and Code !!

Hi Experts ,

I have a custom progrmme , where in the initial screen user give a particular Plant and sales org combi . If the  combination for the group of users (maintained by authorization obj )for that particular plant and sales Org is permissible he/she can go to next screen . In the next screen he can see a list of T-Codes (standard sap) with radio buttons and can execute the same .

Now my requirement is .. I created a new Plant and sales Org and have a grp of authorized users . Now I want when a user enter that particular combination of New Plant and sales Org he can see some "extra" Tcodes in the 2nd Tcodes.These tcodes wont be visible by other grp of user .How can I achieve this via ABAP code.

Thanks

MM_SD