Do you still need help with this question? If so, could you provide an update on where you stand now? Also, is this related to your previous thread How to count - Sample custom field - Time point ?
If you have already found a solution would you mind returning to this thread, replying with the solution, and then marking your reply as the "Correct Answer" to improve visibility?
I have also added tags to this post to make it easier to search.
I marked this as "Assumed Answered" as there was no reply to my initial follow-up. Please let us know if you still need any help and we can pick up from there.