Spreadsheet functions from Apps-Script
Not possible – This has been asked many times. Suggest you check the google-apps-script issue list to see if anything has changed. But last I checked, there is no way to do it, and they have no plan to add it. https://code.google.com/p/google-apps-script-issues/issues/list
Ethercalc – java script spreadsheet formulas
If you need to, you can always copy the code from “ethercalc” as it has a java script versions of the spreadsheet formulas.
https://github.com/audreyt/ethercalc