Get count of records from SELECT

Hi

I have example:

rnum := 0;
FOR r IN EXECUTE ''SELECT *
FROM ''||table_name||''
WHERE var = ''||var
LOOP
IF rnum = 0 THEN
-- how could I get the count of records here ???
-- I tried GET DIAGNOSTICS rcount = ROW_COUNT;
-- BUT it returns ZERO = 0 :(
END IF;
rnum := rnum + 1;
END LOOP;

-- here I will get count of records in "rnum", but I need in LOOP's
-- first step

Many thanx from Zet