@heurteph-ei
Yes, Custom dimensions are fine.
But I need a Custom variable because of the one described reason here:
The only use case where it would make sense to use Custom Variables instead of Custom Dimensions is when a given dimension can have multiple values for a same visitor or page. For example, if you want to track Page categories and a given page or article has more than 1 category. Custom Dimensions feature does not support multiple values per dimension, but you can store multiple values for a same custom variable.
Thank you for you help!
@ForAll: Solution can be found here