General :: Sticky Situation Bcos Of Sticky Bit

Situation is that there are two users on a Linux server- say A and B.A has been operating a shell script that in turn makes use of and exe file.The script and exe both are owned by user A.My problem is that I want user B to make use of the script and exe in exactly the same way user A does.So I have set suid bit of the script, exe and all the library files that the exe uses.But the exe is still not executing from user B.I did a man of chmod on Linux server and it gave an indication that SUID is disabled on new Linux servers.Now the question is, is there any other command that can perform the same task as SUID did on Unix.