san83_deep,
Apologies for not getting back to you sooner - I’ve had problems of my own!
I’m not sure whether you need clarification on the condition object, editing the LOV, or both.
So, if it is the condition object, do you have a week field on your table or are you building this up from date? Let me know and then I’ll think about the syntax although writing the condition object will take me a bit of time.
Have a look at this post and the link to Dave’s articles within it for some inspiration:
https://bobj-board.org/t/95795
Thinking about it, rather than editing the LOV of another object to then use in a prompt, you may as well combine the whole lot in a condition object, prompt as well.
Steve
steveayres 
(BOB member since 2006-11-23)