DT_HIDEPREFIX Windows 2000/XP: Ignores the ampersand (&) prefix character in the text. The letter that follows will not be underlined, but other mnemonic-prefix characters are still processed. For example:
input string: "A&bc&&d"
normal: "Abc&d"
DT_HIDEPREFIX: "Abc&d"
Compare with DT_NOPREFIX and DT_PREFIXONLY.