Your logic is not understandable.
Please elaborate more as Qlikview Engine can join two tables with a common field in them ,in your case there is DESC (as a common field ).
When Qlikview Engine joins, it will use outer join to join both of your tables (as it is according to the data which you have provided for DESC field)
and when you select any field values of FIELDs(H or G),it will give their corresponding value of DESC Field and not the one you explained.
Hope you understand my point.