IndexMatch Conditional Col #Ref Error

Greetings,

I thought I had this issue behind me, but I am unhappy with the huge array that Excel has to calculate whenever the sheet recalculates.

Formula:

=IF(AV4<>"",CELL("address",INDEX($A$3:$BI$203,MATCH(AV4,$AI$3:$AI$203,0),IF(INDIRECT(ADDRESS(BG4,COLUMN(BI4)))<>"",COLUMN(BI4),COLUMN(AO4)))),"")

So I figure easy enough I will just move the dataSet closer to the formula & Excel should have less work to do, well it only works as long as I have a Col A ref for the index, if I change it to say AI where the data is now I get a #Ref error. When I breakdown each of the nested formulas to individual ones they work independently. Well that is untill I get to index & try to give it my new array starting in AI.

Formula:

=IF(AV4<>"",CELL("address",INDEX($AI$3:$BI$203,MATCH(AV4,$AI$3:$AI$203,0),IF(INDIRECT(ADDRESS(BG4,COLUMN(BI4)))<>"",COLUMN(BI4),COLUMN(AO4)))),"")

So I think the more relevant question from me is how would one do indexMatch with a conditional col ref to pass off to the index.

TIA