error LNK2001: unresolved external symbol

[gica]

I try to compile (with VS2008) the well known programm eMule (Scarangel mod) and I have seen this in the end of the BuildLog:

Vinculando...
Creando biblioteca .\release\eMule.lib y objeto .\release\eMule.exp
EMSocket.obj : error LNK2001: símbolo externo "public: unsigned long __thiscall CNetF::GetMSSFromSocket(unsigned int)" (?GetMSSFromSocket@CNetF@@QAEKI@Z) sin resolver
EMSocket.obj : error LNK2001: símbolo externo "class CNetF theNetF" (?theNetF@@3VCNetF@@A) sin resolver
.\release\eMule.exe : fatal error LNK1120: 2 externos sin resolver

Because the eMule forum did not answer me, I ask here how can I solve this fatal error. I think is because it must link with one or some libraries that are not in the project. Someone can help me? What libraries are missing?
(For compiling, I have the files NetF.cpp and NetF.h If it is necessary, I can post the contain of these files)
Thanks in advance.