merging to php comments

Ok i have created a plugin with admin menu.

My admin menu has 52 catagories:
cat1:
cat2:
cat3:
cat4..5..6..etc

in my plugin i want to be able to choose automatically which catagorie comes out on the page.

in the plugin editor i have
$ThisWeek = date(‘w’);

what i want is this.
I want to automatically collect the corrasponding cat depending on what week it is i.e. if it is week 43 then get_option(‘cat43’);.
but there has to be a way of doing it withought 52 if options.

please please can someone help me.