Hi, Oleg!
I don't think I misread your original question...but that's just my opinion...
Here's an example for you to try:
Take Big Class.jmp. Run some ridiculously-overfit Neural Network analysis with Sex as the Response and Age, Height, and Weight as the factors. Consider Female as the Positive case. :)
I got a Contingency Table that looks like this:
Choose Make Into Data Table.
TP= 16. FP=2. FN=2.
F1 can be calculated by 2*TP/(2*TP+FP+FN). I get F1=0.89.
This is a very easy thing to script (in my opinion :), and you can even automatically include this metric (and any other) on any of your output with a script. Give it a shot, and I'll try to help you get it if you fail.
Good luck.