Thought id show how you can pass hParam values to the tool table in mill mode, got the idea from Tuttles lathe project code he created passing values to his tool table.
First thing all macros need to be saved in .mcs extension not .lua
the ZeroBrane defaults to a .lua extension and that bit me.
as I found out they never get compiled in the mcLua.mcc file (why... good question it says lua, right in the name)

I attached the sample code so all can learn and play with.
no way is it clean & refined but gives you an idea how its done and how you can test in the ZeroBrane's debug mode
thanks SMurph making my life even more ...

and yes there are other ways to update the table (G10), this was just a challenge I wanted to learn from.
the default tool is the current tool but you can use and pass a t# to write data to different tools
could be made into a looping routine that cleans out all the data in the table.
its all about whats being passed and how it is used in the function.