kallsyms_lookup_name

Hi, I need to use some unexported kernel symbols in my kernel module but in the particular kernel version i am based on (2.6.18 - RHEL 5.7), kallsyms_lookup_name is not exported and there is no kallsyms_on_each_symbol in this kernel. And I can't change the kernel owing to reasons i have no control over. In this scenario, how do i use unexported symbols. Is there any other mechanism by which i can lookup the address of a kernel symbol. Thanks. Venkatram