VBA for creating dropdown list from dynamic multiple values lookup

Hi everybody,

My questions are so difficult that it's hard to explain them. I will give it a try and please, don't hesitate to ask me further explanations if needed. :)

I attached an excel where I have the following:

- Sheet1: column A is for supplier, column B is for amount, column C should be the invoice
- Sheet2: here I have the database. Column A for supplier, col B for amount and col C for invoice. For demonstration reasons, I concatenated column A and B into new column A. Now I have only col A (concatenated) and column B for invoice.

VBA1: right click sheet1 and view code - this allows to create a custom drop down list from column A
VBA2: simply called "blabla", it will lookup in sheet2 column A values in col B and arrange in col D. Please run it to understand better.

Problem1: for VBA "blabla" I would like to do the same but without concatenate col A and B. To simplify ... eh, can't simplify it.
Problem2: for VBA 1, the "MyList" drop down I would like to be created following the logic: if in sheet1, value from concatenate A&B is found in column D from Sheet2, then that row from sheet2 starting from column E = “MyList”.

Final result: in Sheet1 C1 I should have in drop down list "inv1 ; inv4 ; inv5" , in C2 -> inv11 and in C3 -> inv12 ; inv13

Well, that's it. Hope it's possible and not too hard.

Thank you all,
PS: of course that I'm a beginner, I found those VBA in other threads but couldn't modify the codes correctly.