How to Convert Big Endian to Float?

You guys make this look so easy.
It has been a while since i did any C.

If you don't mind, helping once again - might save me a few days LOL

I am receiving data via serial such as "22 20 20 70 20 05 10 01 22 20 20 70 20 20 10 02 42 9C 00 00 10 03 87 C9"

Is there an easy way to parse the "429C0000" from the result to a variable to your function?
I have been doing something wrong here as it is not working.