Case ( Left ( YourField ; 1 ) = 6 ; "S" )
If there anywhere that gives good examples or explains what functions can/how they wrap into other functions?
At list of what comes first?
Not that I can think of, but it may help if you keep in mind that any place where you can use a calculation, is also a place where you can insert a call to another function to nest function calls inside of function calls.
I also find just sitting down with a simple test file and experimenting to be a good way to figure out ways to get a complex calculation to work.