How can I make Anthropometric Calculator (Z-Score) by KoBoToolbox?

I want to make Anthropometric Calculator by Kobotoolbox Calculation system based on WHO software (WHO Anthro Survey Analyser and other tools). Actually, I want to calculate Weight-for-length Z-Score. Is it possible to do it by the ODK system?

Do you have a formula for the Z-Score?

I don’t have. But I have collected documentation.

and WHO offline software documentation is here: WHO Anthro Survey Analyser and other tools.
Download link:

But I don’t understand how to apply it,