How bult-in Excel sumifs function works

[PG_Develop]

Hello, colleagues

I need to write a user-defined function for Excel with some modification of built-in SUMIFS function.
Could you, please, help me to find the code of this function? Or to find source, where it's algorithm is described in details? I have spent a couple of hours on googling, but found nothing detailed enough

In case, you have some questions, do not hesitate to ask

Thank you in advance!

 

[Special-K99]

I doubt you'll find anything like that.
You might just as well ask if the entire source code for Excel is available on the net. I should think it's not.

You'd be better off explaining what you're trying to achieve in words.
Someone may have a solution.

 

[PG_Develop]

I doubt you'll find anything like that.
You might just as well ask if the entire source code for Excel is available on the net. I should think it's not.

You'd be better off explaining what you're trying to achieve in words.
Someone may have a solution.

Yes, I had the same thoughts, but still hope for luck, that maybe someone found out the logic of that function)

I wrote some modification of this function, but it slows work a lot. You may see code and explanation of it here: https://codereview.stackexchange.com/questions/163090/sumifs3d-user-defined-function

Thank you for your participation in solving the problem!