How do I get the STX character of hex 02

Just a comment to GeoffM's answer (I don't have enough points to comment the proper way).

You should never embed STX (or other characters) that way using only two digits.

If the next character (after "\x02") was a valid hex digit, that would also be parsed and it would be a mess.

string s1 = "\x02End";
string s2 = "\x02" + "End";
string s3 = "\x0002End";

Here, s1 equals ".nd", since 2E is the dot character, while s2 and s3 equal STX + "End".