Execute ignoring cursor?

Hello. Didn't find dedicated plpgsql list, so decided to post question here.
I am trying to create a  function that will pick up some values from cursor and execute them as a dynamic query.
However, once i use EXECUTE, its seems to be ignoring the existence of cursor and try to pick up values from table.
Basically:

insert into mytable ( value, attribute_id, set_id ) (select rec."151", '201', '1')

works, but

execute 'insert into mytable ( value, attribute_id, set_id ) (select rec."151", ''201'', ''1'')'

fails with

ERROR:  missing FROM-clause entry for table "rec"
LINE 1: ...ibute_id, set_id ) (select rec."151",...

Is there any way around it? Or should i just give up and do it some other way?