And if windows supports a bunch of generic ones, any idea how I could use tohse to create F25 on up?
Alas, windows doesn't support generic keys. It only supports the specific keys on the lists I linked. (To be really exact -- and I"m getting pretty technical here -- there are some unassigned key codes that you could pass to programs in certain circumstances, but most programs wouldn't respond since these key codes would just be numbers that don't represent keys.)

So how abouts would I create those keys up to F24?
Here's an example of how you could do this with HotkeyNet. The following hotkey sends F24 to a World of Warcraft window when you press Ctrl F3. (Why Ctrl F3? Well you have to press something to make this happen -- I chose Ctrl F3 at random.)

<Hotkey Ctrl F3>
<sendpc local>
<sendwin "World of Warcraft">
<key F24>