reference GAC assembly with fallback version

Question

My project references version 2.0.0.0 of an assembly in the GAC. If version 2.0.0.0 is not available, I'd like to redirect/change the reference to version number 1.0.0.0.

Some research came up with the following posts, but they don't seem to be directly related to my scenario:
How to provide a fallback assembly instead of the one that can't be loaded?
How to reference to multiple version assembly

I believe that strongly-named assemblies required a specific version number, so I don't think the reference itself can use wildcard (*)? What is the simpliest way to solve my scenario?