Visitor Messages

please can anyone help me.
the idea of the program is to be like
printf("Enter your pin muber:");
but i need to use one of these values in the file i created:
#include <stdio.h>

int main()
{
FILE *customer_infor mation;
char pin_number[4]={101,102,103,1 04};
int test;
customer_inform ation=fopen("cu stomer_informat ion.txt","w");
if(customer_inf ormation==NULL)
{
puts("Error creating file");
return (1);
}

for(test=0;test <4;test++)
fprintf(custome r_information," %d\n",pin_numbe r[test]);
fclose(customer _information);

printf("Pin numbers:");
for(test=0;test <4;test++)
printf("\n%d\n" ,pin_number[test]);