Is this possible? If so, how would one go about it?

FYI, I'm still using GWD Ver. 2.51.

Unfortunately, only by using #include "script.c" directive and then calling
functions from that script. For example:

MyScript1.c:
-------------------------------------------
#define MYSCRIPT1_C

#include "MyScript2.h"

int main(int argc, char *argv[])
{
   // call MyScript2 function
   Script2_Main(argc argv);

   return 0;
}

MyScript2.c:
-------------------------------------------

int Script2_Main(int argc, char *argv[]);

#ifndef MYSCRIPT1_C

int main(int argc, char *argv[])
{
   return Script2_Main(argc argv);
}

#endif

int Script2_Main(int argc, char *argv[])
{
   printf("Script 2 code");
   return 0;
}