So I have a reference formulas created by Concatenate formula. which is spread on 3500+ cells

Here is concatenate formula
CONCATENATE("=","IFERROR","(",CONCATENATE("'",$B$2," ",TEXT($B33,"yyyy"),"\",TEXT($B33,"mmm"),"\","[",TEXT($B33,"ddd, mmm dd"),".xlsb]",CONCATENATE($B$3,C$2))&"+"&CONCATENATE("'",$B$2," ",TEXT($B33,"yyyy"),"\",TEXT($B33,"mmm"),"\","[",TEXT($B33,"ddd, mmm dd"),"_2",".xlsb]",CONCATENATE($B$3,C$2)),",","'",$B$2," ",TEXT($B33,"yyyy"),"\",TEXT($B33,"mmm"),"\","[",TEXT($B33,"ddd, mmm dd"),".xlsb]",CONCATENATE($B$3,C$2))
Which creates formula like this in a cell:
IFERROR('K:\Maint\PLANING\DSC CALENDARS 2019\Apr\[Tue, Apr 02.xlsb]Millright data'!B7+'K:\Maint\PLANING\DSC CALENDARS 2019\Apr\[Tue, Apr 02_2.xlsb]Millright data'!B7,'K:\Maint\PLANING\DSC CALENDARS 2019\Apr\[Tue, Apr 02.xlsb]Millright data'!B7
As you can see it is referenced to specific file. Thing is this file may not exist yet, but may be created in future.

While I can manually make this formula work by:
1) copying concatenate formula and pasting as value (which creates reference formula)
2) replacing "=" with itself (it will also work if I just click inside the cell and hit enter)
3) If one or both files do not exist I need to hit cancel in Update values.
4) even if file doesn't exist yet, once it gets created #REF error changes to referred value.
5) the only serious disadvantage is stored values if referred file gets deleted (,but it is another discussion)

As I said, the formula works, if done manually
When I try to use replace all, it only replacing the first cell after I go through cancel steps

Then it just ignores the fact I chose multiple cells.
Even when I create a macro to replace all cells it just doesn't go further than first cell , even if this cell is already a working formula.

I tried all codes I could find on replace all and update value cancel topics, and none is working in my case I am really confused.
Can you please help to find a right code to make text reference formulas work ?