I need to have these values occupy the same physical space on the report.
Does this mean that if one value is there and not the other you don't want data sometimes showing as if left justified and other times as right justified because data is in either the left or right control? Then you need to hide the 2 controls and add a calculated textbox on the report: =[txtLeft] & " " & [txtRight]
The red part inserts space or whatever you'd need to separate the two values. If you left justify the text in this control, if the left value is Null, the right data will be left justified. If the right is Null, same. If both are there, same.
You should still base a report (and most of the time, forms) on a query as suggested.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.