>This is good only if the hex value is an integer value. It doesn't work if it is a float.

Do you mean that the hex value represents a floating point number stored in a standard format (for example, I think IEEE has one standard)? If so, this can be a real bear to translate because it will have a mantissa component, a sign component, and an exponent component, and the arrangement of the bits depends on whatever standard format is used to represent the number. (My guess is that this is not what you are dealing with).