Todd - when you use the "complex expression" version of CASE, don't list the column name ouside of the WHEN.
As in -
case --<<<<<<--LOOK - remove "pl.desired_recv_date" from here
when pl.desired_recv_date IS NULL
then convert(char(12),po.desired_recv_date,101)
else convert(char(12),pl.desired_recv_date,101)
end as "Line Want Date",
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Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?