Static Lib BCB Project doesn't link imported external functions

Hi,

I'm creating a BCB6 static lib prj (let's call it static.lib), which
should also use functions from an external dll (let's call it
external.dll), and so it should link references to them from its
external.lib.
Unfortunately BCB6 doesn't even ask for the external.lib itself,
compiling and linking the static.lib with no errors.
For instance the following static lib project code compiles and links
perfectly without even asking for the external module containing the
Foo() function :

// TEST.H
#ifndef testH
#define testH
extern "C" __declspec(dllimport) double __stdcall Foo(double x);

double UseFoo(double x);
#endif

//TEST.CPP
//---------------------------------------------------------------------------
#pragma hdrstop
#include "test.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)

double UseFoo(double x){
    return Foo(x*2.0);

Quote
};

What's wrong with it?
I tried several possible workarounds with no results, obviously I'm
soing something wrong, but what?
If I compile it as DLL project then everything is fine and BCB asks
for the unresolved external function which is satisfied only if a add
the external.lib to the project.
Why doesnt't happen the same with a static lib project?

TIA and regards