sql has the ability to update a table based on another table, you just need to get used to the syntax.
the advantage is it would be set based,and allow you to avoid a cursor or loop.
If you can post some details, we could help
UPDATE myTarget
here's a mockup example:
UPDATE myTarget
SET myTarget.ColumnName = OtherTable.OtherColumnName
FROM myRealTable myTarget --an alias on the real table to update
LEFT OUTER JOIN OtherTable
ON myTarget.PK = OtherTable.PK
WHERE myTarget.StatusColumn IS NULL
AND OtherTable.ProcessedDate IS NOT NULL
SET myTarget
Lowell