C:\_32\c>cl double_test.c double.lib
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.00.9466 for 80x86
Copyright (C) Microsoft Corporation 1984-2001. All rights reserved.

double_test.c
Microsoft (R) Incremental Linker Version 7.00.9466
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:double_test.exe
double_test.obj
double.lib
double_test.obj : error LNK2019: unresolved external symbol _my_double reference
d in function _main
double_test.exe : fatal error LNK1120: 1 unresolved externals

C:\_32\c>