Linker error while connecting static library with DLL

[forstudy3]

0I have a static library in which class with log4net is defined.something like this -

public ref class CustomLog
{ 
public:
static log4net::ILog^ m_logger;

log4net::ILog^ SetLogger();
};

This static library is then used to connect to another C++ DLL - I have added header file used for this log class in C++ DLL also added static library reference in additional dependency.WHen I ma trying to compile this DLL getting following linking error -

error LNK2020: unresolved token (06000003) CustomLog::SetLogger

I am using VS 2008.
Please let me know how to resolve this issue.