[Rd] Strange problems with compiling dll

[Oleksandr Dyklevych]

Dear sir\madam!

I'm trying to speed up my R code by writing quite simple dll's in C. But I
faced some problems, and I cannot determine their source.

#include <Rinternals.h>

SEXP mycombin(SEXP N, SEXP k){
       int i, *j, *l, c;
       j = INTEGER(k);l = INTEGER(N);
       c = 1;
       if(j[0] > 0 && j[0] < l[0]){
           if(j[0] <= l[0] - j[0]){
               for(i = l[0]; i >= l[0] - j[0] + 1; i--){
                   c = c * i / (l[0] - i + 1);
               }
           }
           else{
               for(i = l[0]; i <= j[0] + 1; i++){
                   c = c * i / (l[0] - i + 1);
               }
           }
       }
       return ScalarInteger(c);
}

But, when I try to compile it I have 5 errors, and all of them come form
linker and say next (Code::Blocks):

||=== mcb2, Release ===|
obj\Release\conv.o:conv.c|| undefined reference to `INTEGER'|
obj\Release\conv.o:conv.c|| undefined reference to `INTEGER'|
obj\Release\conv.o:conv.c|| undefined reference to `Rf_ScalarInteger'|
obj\Release\conv.o:conv.c|| undefined reference to `Rf_ScalarInteger'|
obj\Release\conv.o:conv.c|| undefined reference to `Rf_ScalarInteger'|
||=== Build finished: 5 errors, 0 warnings ===|


I found out that I need to link Rdll.lib, but to make it I should use
these instructions

make R.exp
lib /def:R.exp /out:Rdll.lib

but i cannot figure out where I should use them.
I'm trying from here C:\Rtools\src\gnuwin32 but each time i get
make: *** No rule to make target `R.exp'.  Stop.

So where should I state this rule and which rule?...

Will you help me, please, to "connect" my C compiler to R?

Best regards,
Oleksandr