substring - A patterned irregular splitting of a number into many parts of its digits in C#? -

whenever given 11-digit number (like 12345678901, 82344678971 etc.), want partition 4 parts 5digits-4digits-1digit-1digit always. so:
12345678901 -> 12345 6789 0 1
82344674971 -> 82344 6749 7 1

i saw similar question in sof uses regular blocks; namely same number of digits: splitting string / number every nth character / number?

i want function take 11-digit (long) integer parameter, , return above way; able block want: example, splitinparts(1) return 12345; splitinparts(2) return 6789; splitinparts(3) return 0; splitinparts(4) return 1. 82344674971: 82344, 6749, 7, 1 respectively.

being novice in c#, not achieve how perform above via c#.

use function use substring.

 private string getmysubstring(long value, int splitpart)   {      string str = value.tostring();       if (str.length != 11) return "invalid number lenght";       string sub1 = str.substring(0, 5);      string sub2 = str.substring(5, 4);      string sub3 = str.substring(9, 1);      string sub4 = str.substring(10, 1);       switch (splitpart)      {         case 1:            return sub1;         case 2:            return sub2;         case 3:            return sub3;         case 4:            return sub4;         default:            return "invalid part number";      }   } 

use "value" original value want split , "splitpart" number of part want extract. hope asking if want , can convert returned string integer