Set a field value based on the number of some multiplechoice fields

The scenario is this:

I have some conditional fields that are supposed to set the end result value of another field.

I can't use the default conditional rules knack offers because they lack the ability to count the number of choices the user has checked, wich is determinant for the end result, also record rules are not applied here because I need the user to see the changes on the page.

  • Field Condition1 is a multiplechoice, if the user selects 3 of more from this the RESULT field must be set to FALSE.
  • Field Condition2 is a multiplechoice, if the user selects ANY one from this the RESULT field must be set to FALSE.
  • Field RESULT is a multiplechoice to store the result.

So, the Field "RESULT," is always TRUE, unless the user selects 3 or more options from "Condition1" OR any option from "Condition2"

How can we get it to work on the page where the user actually sees the RESULT beeing changed based on his choices ?

Thanks