Update specific rows in a column

I have a column with 82 rows(from table1) and I want to update just the 76 rows in it with different values from another table(table2). Avoiding 6 specific rows(1, 10, 38, 39, 46, 77). Leaving these rows with null values. I used cursor to save all the 76 rows from my table2 Cursor my_cur Is Select * from table2 Then I tried to update my table1 Begin For x in my_cur loop Update table1 Set my_col = x.acct_num Where rnum not in ('1', '10', '38', '39', '46', '77'); end loop; End; But I ended up updating these rows with same value(only 1 acct_num to all 76 rows). It seems that the last value(acct_num) from my cursor was the only one im always getting. I want to enter different acct_num to 76 rows and in the same order as in my table2 I added rownum in both of them to have at least be sure what rows to skip. Any ideas how to do it? Thanks.