how to creat online database server

I have a local database called nse2007.dbs and remote database called MXAG, on the remote database i have a table called TB_REMOTE, in my local database i have three users: ADMIN01, USER01 and USER02, in ADMIN01 schema i create a dblink as: create database link dbl_mxag connect to sistemas identified by sistemas using ‘mxag’;
Now i want to give to only USER01 access to the remote table via database link but not to USER02,
How i can do it?