Create new extension and implement mathematical method in the template

[Anonymous]

Hi Guys,

I desperately need your help. I'm new to Qlik Sense Desktop and I'm over-demanding with the task.
I need to create a new extension in Dev Hub.
It has to implement in a template (e.g., chart template) a mathematical method (e.g., turnover - cost = profit). Is that possible ?
Give examples where you can compare it.
I look forward to your answers

Best regards
Soner