Need help w/return value of duplicate cell

Have a tricky one... can this be done?? Refers to cells E4 and D4 of current worksheet "One_Rig_Response"

-In current worksheet "One_Rig_Response" I need to write a formula into E4.
-E4 currently refers to cell/worksheet "=ZoneList!V3"
-D4 currently refers to cell/worksheet "=ZoneList!B3"
-E4 cannot, however, duplicate cell D4
-If E4 is the same as D4, I need cell E4 to refer to the cell next to "=ZoneList!V3", which is "=ZoneList!W3".
-And if THAT cell is still returns the same value, then I need to go to the NEXT cell beside that, "=ZoneList!X3"
-And finally, if that cell still returns the same value, then onto the next cell, "=ZoneList!Y3"

Is this possible????

Also, I will be highlighting and dragging/copying this formula down a column, so I cannot make it specific to those exact cells.

Thank you so much! Here is the excel worksheet with just three worksheets in question. Every cell refers back to ZoneList worksheet. I am trying to create a formula for all columns labeled "HE".

IN HIGH RESCUE WORKSHEET:
-Cells in column D refers to the corresponding cells in Column B of ZoneList.
-Cells in Column E need to refer to columns V-Y in ZoneList, with the first attempt being column V, and so on.

For example, in "HIGH RESCUE" worksheet, working with Row 4, specifically cells D4 ("=ZoneList!B3") and E4 ("=ZoneList!V3").
-They are currently showing both "E06" as their returned values. However, they cannot be the same in this worksheet.
-So cell E4 needs to go to the next-up cell ("=ZoneList!W3").
-And so on... if those are also the same... then next being "=ZoneList!X3," next up being "=ZoneList!Y3."
EXAMPLE: In "HIGH RESCUE" E4 should show TK1 ("=ZoneList!W3"), since ZoneList!V3 (E06) is the same as D4 (E06). It should move on in order: V-W-X-Y.



I would be happy with just that, but if anyone can also help with the other worksheet, "9 Engines Deep", Columns W-Z also need to be updated the same way, however:
-anything in "2HE" (column X), cannot duplicate cells from Columns B-C and L-M.
-anything in "3HE" (column Y), cannot duplicate cells from Columns B-D and L-N.
-anything in "4HE" (column Z), cannot duplicate cells from Columns B-E and L-O.
If there are no unique numbers to return for any particular cell (or all apparatus have already been used), it should be NULL.

Thank you so much! Hope I didn't make that more difficult than it is

(hope the attached spreadsheet goes through, if not I will try to post again)

I reduced the spreadsheet down to just a few rows since it exceeded size

Amazing! Thank you soooo much ))))

Thanks so much for all your help! I ended up adding the AND function to the formula with each column to add on the extra values. That was before I saw this.

Yes, this is to reduce response times for our department, so I am very grateful for your help. I will check this "solved." Have a blessed day!