After much trial and error, yes I was able to finally get it to work. Here's the code I used.
Code:
SELECT qry_MainSum.[Case Number], qry_MainSum.Examiner, qry_MainSum.[Date of Assignment], qry_LooseDriveSums.[Number ofLoose Drives], qry_LooseDriveSums.[Loose Drive Total], qry_HDSums.[Number of HD], qry_HDSums.[HD Total], Nz([Loose Drive Total])+Nz([HD Total]) AS [Total Processed]
FROM (qry_MainSum LEFT JOIN qry_LooseDriveSums ON qry_MainSum.[Case Number] = qry_LooseDriveSums.[Case Number]) LEFT JOIN qry_HDSums ON qry_MainSum.[Case Number] = qry_HDSums.[Case Number];
I then had an issue with Count and Sum showing no values due to some of the data being blank, but Nz in the calculations fixed that.
I'm sorry I really can't be more specific on how I fixed it, I just was able to by trial and error like I said.