When you format a string from a number, you can pad it with zeroes for example with sprint (string, "%08d", number); this instructions creates a string of (at least) 8 characters padding with zeroes to the left if the number is lower than 99999999; if greater resulting string will be enlarged consequently.
Next you can use strncpy (or StringCopyMax) and strcpy to split the string in two substrings.
