A pretty basic Hex conversion problem

I have to set 14 to the register.

This is the mistake in thinking. In C++ there is a difference between 14, 0x14, and 014 (yes, the leading 0 makes a difference). The first is a decimal constant, the second a hexidecimal constant, the 3rd an octal constant. All three are different numbers.

0x10 + 0x4 is not 14, it is 0x14. 14 is equal to 0xE, and 0x14 is equal to 20.

How do you really set a register with this table ?

The best way it to do what I showed you, use #define to give names to the constants and either add (+) or bitwise-or (|) them together.

for example, whats the effect of 14 ? first or second ?

The second, because 14 is equivalent to 0xE.