problem in creating a library

Hi

I want to create a library (.lib) for such a function:

#define baud 19200
#define fpclk 12000000

void setbaud (void);

as a header file (set.h) and

void setbaud (void){
unsigned short int a=(fpclk/16/baud);
.
.
.
}

as a .c file (set.c).

compiler gives me a .lib file format and I've add it to my UVproject

and every thing is OK but when I try to write a new #define for baud and fpclk, compiler can compile without any error or warning but every thing is fixed same as those definitions which are mentioned in library(here they're always 19200 and 12000000).

if I remove them in library I'll get an error.

how can I set my library to get such information from outside of library.
(Rl-ARM is in this way without any kind of problem)

thanks in advance