Okay, do you want to know what something references, or do you want to know
what something is referenced by? Also, do you want to know at runtime
through code or just run some tool at the command line?
There is no "backwards" in assemblies. For instance, if you have Foo.exe
which references Bar.dll, well, you can open Foo.exe with reflector and it
will tell you that Bar.dll is referenced. However, Bar.dll could also be
referenced by MyCoolProgram.exe. Do, as you can see, there can be no
relationship back from the assembly.