#include <string.h>

char *strreplace (char *string, int start, int num, char *repstr )
{
    int x = 0;
    char *success;

    --start;
    /* "start" becomes zero relative */
    if ( start < strlen (string) ) {
        while ( string[start] != '\0' && *repstr != '\0' && x < num )
            { string[start++] = *repstr;  ++repstr; x++; }
        success = string;
    }
    else
        success = NULL;

    return (success);
}