During a setup creation process, I am planning to do the following (within a C# Script):
Why don't you, during build process, read the
AssemblyFileVersion of one DLL, and save it back to other csproject's
AssemblyInfo.cs, only then compile it?
As a matter of fact, I don't know whether it is possible to modify the DLL file directly, without resorting to something fanciful.
Or alternatively, make sure that all your DLLs share one common
AssemblyInfo.cs. You can do this by adding the
AssemblyInfo.cs as "Add As Link" when you add a new item in csproject. In this way when you do a compilation, all the DLLs will share the same
AssemblyInfo.cs, and thus output the same