How to override the Revision Number generation without writing an AssemblyInfo

In my MSBuild process I have used both Community Tasks Version and AssemblyInfo to achieve custom revision Number generation wherein the Revision Number is set to the TeamCity Build Number.

The desired end result is a File Version value of "2.3.5.nn" where nn is the TeamCity generated Build Number value and "2.3.5" (Major,Minor,Build) is in the AssemblyInfo.cs as below

The standard build process takes my AssemblyInfo as follows:

[assembly: AssemblyVersion("3.2.5.*")]

and the normal build process transforms the '*' WITHOUT updating the AssemblyInfo.cs.

My question is:

Which target can I get at so that I can inject the value to override the RevisionNumber generation  I want without having to update the AssemblyInfo.cs in the project?