triple cascade of drop lists - validation

[clivezgo]

Dropdown Lists / Validation rules
Trying to input information across three decisions

1. Dept 2. Sector 3. Reason

[TABLE="width: 435"]
<tbody>[TR]
[TD]E2
[/TD]
[TD]F2
[/TD]
[TD]G2
[/TD]
[/TR]
[TR]
[TD]dept
[/TD]
[TD]sector
[/TD]
[TD]reason
[/TD]
[/TR]
[TR]
[TD]Hoist_Pins
[/TD]
[TD]Infeed Conveyor 1
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
</tbody>[/TABLE]
Using named excel tables I have successfully managed to make a ‘Dept’ downdrop list, using the table below and index/match its headers . The result is used for the sector dropdown list which gives the correct result.
[TABLE="width: 417"]
<tbody>[TR]
[TD][/TD]
[TD]Trucks
[/TD]
[TD]Hoist_Pins
[/TD]
[/TR]
[TR]
[TD]Trucks
[/TD]
[TD]General
[/TD]
[TD]General
[/TD]
[/TR]
[TR]
[TD]Hoist_Pins
[/TD]
[TD][/TD]
[TD]Infeed Conveyor 1
[/TD]
[/TR]
[TR]
[TD]Grader
[/TD]
[TD][/TD]
[TD]Infeed Conveyor 2
[/TD]
[/TR]
[TR]
[TD]G_Eye_Scanners
[/TD]
[TD][/TD]
[TD]Hoist
[/TD]
[/TR]
[TR]
[TD]
[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
</tbody>[/TABLE]
Table of Dept/Sectors

Next, I want to use an individual Sector table, example Hoist_pins table to produce a droplist for infeed conveyor 1 listing the reasons.
These 'sector tables' are dynamic excel tables on individual named sheets.

[TABLE="width: 548"]
<tbody>[TR]
[TD]Hoist_Pins_Table
[/TD]
[TD]General
[/TD]
[TD]Infeed Conveyor 1
[/TD]
[TD]Infeed Conveyor 2
[/TD]
[/TR]
[TR]
[TD]General
[/TD]
[TD]Accident
[/TD]
[TD]Bearing
[/TD]
[TD]Bearing
[/TD]
[/TR]
[TR]
[TD]Infeed Conveyor 1
[/TD]
[TD]E-Stop
[/TD]
[TD]Cable Fault
[/TD]
[TD]Cable Fault
[/TD]
[/TR]
[TR]
[TD]Infeed Conveyor 2
[/TD]
[TD]Safety Gate
[/TD]
[TD]Chains
[/TD]
[TD]Chains
[/TD]
[/TR]
[TR]
[TD]Hoist
[/TD]
[TD][/TD]
[TD]Jam Up / Pile Up
[/TD]
[TD]Jam Up / Pile Up
[/TD]
[/TR]
[TR]
[TD]Hoist Non-Stops
[/TD]
[TD][/TD]
[TD]Motor Faulty
[/TD]
[TD]Motor Faulty
[/TD]
[/TR]
[TR]
[TD]Pin Chute
[/TD]
[TD][/TD]
[TD]Sensor Faulty
[/TD]
[TD]Sensor Faulty
[/TD]
[/TR]
[TR]
[TD]Pin Belt Conveyor
[/TD]
[TD][/TD]
[TD]Tripped Out - Elect
[/TD]
[TD]Tripped Out - Elect
[/TD]
[/TR]
[TR]
[TD]Pin Shaker Tray
[/TD]
[TD][/TD]
[TD]Twisted Pack
[/TD]
[TD]Twisted Pack
[/TD]
[/TR]
</tbody>[/TABLE]
This hoist_pins table of sector/faults is named hoist_pins

I cannot make a validation rule based on the 2 previous selections to point to these sector tables and their dropdown lists ….Am I missing something?
I have tried to substitute the table names in the validation box …=INDIRECT(SUBSTITUTE("dummy","dummy",E2)), try and get to the correct sector/faults table.
But is gives the sector list again not finding the correct table or the correct column.
There are different tables for each dept.

thank you for any help..