Zend certified PHP/Magento developer

Join/Mix dynamic and static values on Array = alternative to HSTACK that works in older MS Excel version (No VBA, please)

I need to join some value(s) from some cell(s) with a “static” bunch of other values into an Excel array… BUT I’d like to avoid using VBA for it and I need something that works also with older Excel version: at least MSO Excel 2010.

I know I could get what I need very easily in MSO Excel 365, without VBA, by simply using HSTAK function, for example this way: =SUMPRODUCT(CONCATENATE(HSTACK($A$1,"Const1","Const2","Const3"),"/",K$2)*1)

(Don’t mind the result: that is a very simplified representative version of my real formula, anyway it suffice to focus on the matter here.)
HSTACK would let me obtain the “mixed dynamic/static array” I need, and it works …BUT only on MS Excel 365, unfortunately.
As I said, I need a way to make things work also on older Excel version (at least Excel 2010), so…
Ultimately: looking for an alternative I can’t figure out myself… can you help me please?

P.S.
I tried to do without HSTACK this way: =SUMPRODUCT(CONCATENATE({$A$1,"Const1","Const2","Const3"},"/",K$2)*1)
but it gives error! (Of course, dynamic and static values can’t be joined together into an Excel array that way…)