Linking problems when extending ns

[T.Hval]

Hi!
I am writing an application for ns, and I am having some slight problems
getting my code to link because of undefined references. So I was
wondering if somebody could tell me the location of the following "ns"
symbols, I have been unable to locate them myself.

'dlerror','dlopen', 'dlsym'  which /usr/lib/libtcl8.0.so tries to use.
'et_ns_ptypes', 'et_ns_lib' which ns-2.1b5/tclAppInit.cc tries to use
`version_string' which ns-2.1b5/misc.cc tries to use


Thanks in advance

Tor Hval