This is a Caesar Cipher that I took on and developed myself. See https://github.com/SniffingTiger/Caesar-Cipher/blob/master/Dynamics365_CaesarCipher/Program.cs for the main program code.
The program takes in a string formatted as ####:cccccccccccc and encrypts the string that follows the colon using the number specified in the beginning of the string. It shifts the numbers left if the number is negative, and to the right if the number is positive. You can shift the characters up to 1 Billion places to the right or to the left. Up to 200 characters to be encrypted.