If you are a paying member you can add caches to the virtual GPS. There you can filter on all parameter of the cache that are listed and elevation i one of them.
The problem is that the caches has to be added to the VGPS with for example map compare. The problem i that all caches you what to look at the data for has to be added and mapcompare only shows max 10000 caches and you have to split the result. The PQ splitter can probably be used for this
It you whant to add all your finds it no problem if you have <10000 find ans you have to split the result by some parameter for more finds.
If the elevation is for a challenge please post the GC coded to add a checker. If it is a simpel caches with specific elevations scripts existe