Is it possible to keep the pH in a particular spot higher (for specific plants) than the surrounding soil by burying a large piece of rock underneath the roots?

Let's say I have slightly acidic/neutral soil and have a shady border full of ferns, hostas etc...but I want to grow Cypripedium calceolus amongst them (which prefers calcerous soil); can I plant it on top of/amonst a large piece of limestone? It'll be more long term than spreading grains or eggshells on top of the soil every year.

Thoughts?

What about sinking a container in the ground with plenty of drainage and filling it with your higher pH amended soil?

Because the orchid will eventually outgrow the basket, a more well drained pot acts as a sump for the surrounding and because the amended soil eventually needs replacing or re-amending which I want to refrain from.
Well not that it would be so much trouble, but I'm curious if my idea would work....

Pieces of Limestone will affect soil better than a chunk, assuming it works.