QlikView challenging match logic

Hi all, I need some help with a QlikView logic which keeps challenging me so far. We have 2 tables loaded onto QlikView server.

TableA and TableB.

TableA has columns 'AValue1' and 'AValue2'.

TableB has 'BValue1', 'BValue2', 'BValue3' and 'BValue4', 'BValue5'.

The logic goes like that (translated from vb script)

For each line in TableA

i) if (BValue1 <= AValue1 <= BValue3) and (BValue2 <= AValue2 <= BValue4) then return 'BValue5'

ii) if the first condition is not met, run the following:

if AValue1 exists in TableB.BValue1, then check:

if BValue2 <=AValue2<=BValue4, then return 'BValue5'

iii) if the second condition is not met, run the following:

if AValue2 exists in TableB.BValue2, then check:

if BValue1 <= AValue1 <= BValue3 then, return 'BValue5'.

iv) if nothing from the above is complete, then return blank.
Table2 has many blank values in all its different columns *
How the above can be built in QlikView?
Thanks in advance.