ComboBox with two LinkedCell

I have to fill out two cells (lets say A10 and A11), with the same data taken from a list of given data. The given data is placed in one column.
I have created Combo Box where the ListFillRange is the given data area and in the LinkedCell I tried to write two cells but Excel doesn’t accept list of two cells.
For example, I tried to write in the LinkedCell A10,A11 and A10:A11 and A10;A11 but none of this syntax worked.

I can’t write A10 only in the LinkedCell and then to write a function A11=A10 in cell A11, because in some cases the content of cell A11 will be changed by another Combo Box linked to cell A11 and that Combo Box will override any function that will be written in A11.

Can someone help instructing me how to create Combo Box that writes the selected data into two cells?