Code:
#define _CRT_SECURE_NO_WARNINGS
//#include <stdlib.h>                                                    // used by atoi and malloc
#include <stdio.h>                                                        // printf library
#include <string.h>                                                        // library manipulates strings.


char message_cache1[240];
char message_cache2[240];


int main() {
    FILE *fp;
    char filename[]="ABseeD002.txt";
    fp=fopen(filename, "w");
    if (fp == NULL) { printf("\n The file %s could not be opened.", filename); } //  if error occurs
    printf("Items will be initiated in the same DIRECTORY as this program. Enter EXIT on a BLANK line to exit.\n"); 
    printf("Please enter a message you desire to encode. Limited to 100 characters per line.\n:");                                                
    gets(message_cache1); //  gets message from keyboard
    while (!strstr(message_cache1, "EXIT")) {
        printf("\nlengthofcache1:%d\n", strlen(message_cache1));
        if ((strlen(message_cache1)) > 5) { 
            for (int i = 5; i < 240; i++) { 
                if (message_cache1[i]!=NULL) { message_cache2[i-5] = message_cache1[i];    }
            }
            printf("\nlengthofcache2:%d\n", strlen(message_cache2));
        }
        printf("\n%s\n", message_cache1);
        printf("\n%s\n", message_cache2);
        for  (int count=0; count <=4; count++) // review for loops maybe sing a song about them.
            {
                int ascii_cache=message_cache1[count];
                if (ascii_cache >= 32 && ascii_cache <= 99)     {    fprintf(fp, "0");                    } // dump the leading 0 to file.
                if (ascii_cache != 0)                            {    fprintf(fp, "%d", ascii_cache);        } // dump to file.    %d = integer    
            }
        fprintf(fp, "\n");
        strcpy(message_cache1, "");                        // message 1 empty
        printf("\nlengthofcache1:%d\n", strlen(message_cache1));
        printf(":%s", message_cache2);                    // prints message 2
        gets(message_cache1);                            // gets new message1
        printf("\nlengthofcache1:%d\n", strlen(message_cache1));
        strcat(message_cache2, message_cache1);            // adds message1 to message2
        strcpy(message_cache1, "");                        // message 1 empty
        //printf("\nMessage1:%s", strlen(message_cache1));
        //puts(message_cache1);
        strcpy(message_cache1, message_cache2);            // copies 1 to 2
        strcpy(message_cache2, "");                        // empties 2
        printf("\nlengthofcache1:%d\n", strlen(message_cache1));
        printf("\nlengthofcache2:%d\n", strlen(message_cache2));
        printf("\n%s\n", message_cache1);
        printf("\n%s\n", message_cache2);
    }
    fclose(fp);  // closes the cfile pointer 
    printf("Encoding....completed to the file %s.", filename);
    return 0;
}


INPUT 123456
OUTPUT:
049050051052053
054051052053