From PC hardware perspective need more info. Fwiw these are the areas I'd look into. Sorry if its not well constructed but it is a brain storm from years gone by.
CPU / RAM / DISK / NETWORK can all effect performance. They would be key areas to check. You can do this using Open Resource Meter and see what are the top processes utlising these key elements. .
There then is the CPU type and amount of cache it has available for it. Higher the CPU chipset/type and Cache better the performance.
Graphics not likely to be factor unless you are drawing fancy fast charts.
There are solid-hard drives which can also improve performance if you are doing read/writes. In my time large DBs based on weather apps was Read or Write intensive could benefit from mirrored or striped RAID configuration but I don't remember now. I think striping was better fro disk writes. However, that's more server side and I suspect with solid drives may not be better performance. I'm going to assume you simply have a standalone system wiht no input output dependencies, otherwise bandwidth and network speeds will become a factor too.
You would need to monitor your PC from opening file, running your XLS to closing it to read counters to tell you what's happening under the bonnet so to speak. You say you have lots of RAM but any dirty pages may mean you need more ram or faster disk.
There is the obvious things to check too like make sure you are using a 64 bit HW with a 64-bit OS and 64-bit Excel. If any of those are running 32 bit then obviously upgrade wd help also.
With CPU's interrupt requests are always heavy. If you have lots of stuff connected to your PC like fancy mice and keyboards and other stuff, they can slow CPU.
Quality of motherboard is also likely to be a factor but haven't looked at them for a while now.
I also agree with Malaguti but I'm not so much as a developer. Peeps writing VB scripts or macros can help with that. I don't understand why you need 23000 lines for two variables to be calculated.
I'm going to assume you have deep pockets and money is no object. Good luck.
Going off track but I hope you realise TA doesn't work. History pretty irrelevant on future price imo. Either way wishing you all the best and good luck.