If you just need some indication in which week you've executed a job then why not just store the execution date as a SAS date value. This would avoid the need to maintain some permanent table for maintaining some execution counter ...and the additional logic required to not increase this counter when re-running in the same week because something went wrong the first time.
If you just store the date as a SAS Date value then you can always use SAS functions like intck() or week() to derive week counts.
Below some sample code showing options.
%let first_run_dt='1jan2020'd;
data test;
set sashelp.class;
week_num_1=intck('week',&first_run_dt,today());
week_num_2=week(today());
yyww_num=input(cats(year(today()),put(week(today()),z2.)),16.);
dt=today();
format dt weekv.;
run;
