Hi,
You can use joins in update queries much like you could in a select. This should solve your issue. Also, please post using the (code) forum formatting shortcuts so that things like table data appear in fixed-width font as it's much easier to read...
Anyhow,
update TIEWF
Set TIEWF.Status = W.cod_Status,
TIEWF.Approver = W.cod_approver
from #tmpIEWorkflow TIEWF
inner join IEWorkflow W
on TIEWF.IExpenseID = W.IExpenseID
and TIEWF.num_Lev = W.num_lev
and W.num_seq = 10
and W.cod_status not in ('FWD', 'AWB', 'FDB')
Where TIEWF.Status = 'FWD'
If multiple rows in W match up with TIEWF then you could have the update happening multiple times which isn't really predicable. If this is the case then instead of joining directly to IEWorkflow you could join to a subquery that selects the most appropriate rows form IEWorkflow instead.