Mapping Fields based on unknown relationship
You can use FOR XML PATH to help construct a dynamic query:

-- Generate a list of field names to be used in the SELECT statement
DECLARE @Sql VARCHAR(MAX) =
(
    SELECT '[' + FieldNumber + '] AS [' + FieldName + '],'
    FROM Datas
    ORDER BY FieldName DESC -- Sample column ordering
    FOR XML PATH('')
)

-- Generate a SELECT query; make sure to remove the comma after the last field
SET @Sql = 'SELECT ' + SUBSTRING(@Sql,1, LEN(@Sql) - 1) + ' FROM dbo.ScannedDataCapture'

-- Show SQL before execution
PRINT @Sql
EXEC sp_sqlexec @Sql