I've a string representation of a 39-characters long decimal integer.
I need to convert this into hex format in C#.
eg. 340282366920938463463374607431768211455 (39 characters)
-> ffffffffffffffffffffffffffffffff (32 characters)
By the same token, I need to be able to reverse the operation from hex to decimal.
I am using C# .NET 3.5 which hasn't got BigInteger.
Any advice please. Thanks in advance.