here's the query:

SELECT *
FROM (SELECT [Occurrence Number], [Occurrence Date], [1 0 Preanalytical (Before Testing)], [Cup Type], NULL as [2 0 Analytical (Testing Phase)], [2 0 Area], NULL as [3 0 Postanalytical ( After Testing)],NULL as  [4 0 Other], [Practice Code], [Specimen ID #] FROM [Lab Occurrence Form] 
WHERE NOT ([1 0 Preanalytical (Before Testing)] IS NULL)
  UNION
  SELECT [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],[2 0 Analytical (Testing Phase)],  [2 0 Area], NULL,NULL, [Practice Code], [Specimen ID #] FROM  [Lab Occurrence Form]  WHERE NOT ([2 0 Analytical (Testing Phase)] IS NULL)
  UNION
  SELECT  [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],NULL,  [2 0 Area], [3 0 Postanalytical ( After Testing)],NULL, [Practice Code], [Specimen ID #] FROM  [Lab Occurrence Form]  WHERE NOT ([3 0 Postanalytical ( After Testing)] IS NULL)
 UNION
  SELECT  [Occurrence Number],  [Occurrence Date],NULL, [Cup Type],NULL, [2 0 Area], NULL,  [4 0 Other] FROM  [Lab Occurrence Form], [Practice Code], [Specimen ID #]  WHERE NOT ([4 0 Other] IS NULL)
)  AS mySubQuery
ORDER BY mySubQuery.[Occurrence Number];

for some reason it doesnt like [Practice Code]. it's definitely a column in the table so i dont understand the problem.

the error is

the microsoft office access database engine cannot find the input table or query 'Practice Code'........