Conditioned constraints for repeated questions group


We are designing an ODK form using excel 2016 with a series of repeated questions that we need to put the below conditions or constraints based on the answers chosen:
(i) serial number for the household member, "integer" question type, we want it to start by 1, followed by 2, 3, 4... up until 30. so in that case if we put in default 1 it will be for all the repetitions and enumerators can skip this question with wrong answer
(ii) household member relation to head of household, "select_one" question type, we want the option "head of household" (option 1) to be filled in the first repetition of the questions.
(iii) when option "head of household" is chosen, "date" question type, we need to make sure that the date of birth selected is not earlier than 31 December 2020 having already a constraint that the date of birth does not exceed 2020.

Appreciate your support in finding the formulas that should be used in which columns.
Thanks :slight_smile: