The question / idea really makes no sense. Either buy another monitor with the resolution 5120x1440 or buy a better graphics card. There is, for example, the Dell UltraSharp U4919DW, which is even larger (49 inch diagonal), has the same number of pixels 5120 in width, but only 1440 in height and costs less.

This desired resolution of yours really makes no sense, rather take a smaller/cheaper monitor.

That doesn't make sense, so it's better to use a cheaper monitor.
The monitor cannot simply conjure up the missing pixels.