cant sort table differently without changing formula results

As you've discovered, references point to cells, not to their contents. When you sort a list, it's the contents which change, not the cell references. Luckily, it's possible to get round the problem - here's some methods - which one you choose will depend on your exact circumstances.

Indirect - fixed
If the reference is always E11, then replace E11 with INDIRECT("E11"), like this:
=IFERROR((INDIRECT("E11")*'PAS TAL 1a'!I6*52/1000),"")

Indirect - changing column
If you want to be able to drag the formula along/down with the column changing but the row staying the same, it's a bit more complicated. Replace E$11 with: INDIRECT(SUBSTITUTE(ADDRESS(1,COLUMN(E11),4),1,"")&"$11") which makes your formula this:
=IFERROR((INDIRECT(SUBSTITUTE(ADDRESS(1,COLUMN(E11),4),1,"")&"$11")*'PAS TAL 1a'!I6*52/1000),"")

Lookup using Helper column
Neither of the two options above will work if you want to be able to copy and paste an entire table to another location and keep the formula working. Instead, you can do this:
1. Insert an additional column to the right of your data - let's assume the new column is column H. It must be next to the data, so that it will be sorted with the data.
2. In this column, in the row corresponding to the data you want to refer to (E$11, so row 11, so cell H11), type 'Ref' (without inverted commas) or something else which indicates to you that this is the row you want to refer to.
3. E$11 in your formula can now be replaced with an Index/Match formula which looks up the row containing 'Ref'. This I/M formula is something like this: =INDEX($E$1:$E$15,MATCH("Ref",$H$1:$H$15,0)). The part in red is the column containing E$11. The part in blue is the column containing 'Ref'.
4. You can now put this I/M formula inside your own formula, like this:
=IFERROR((INDEX($E$1:$E$15,MATCH("Ref",$H$1:$H$15,0))*'PAS TAL 1a'!I6*52/1000),"")

If you sort one of the columns, then the 'Ref' will move with the sort, so that it will always find the row in column E which corresponds.



Hope that helps. If something doesn't make sense, just ask!

You're welcome, glad I could help.

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