You cannot. When you build an application using a particular version n of the CVI IDE, the version of the runtime where you run that application needs to be n or higher.
If you need to distribute your application or DLL to machines that have an older runtime, I suggest that you create a distribution kit in the machine where you developed the application. That distribution kit will include the version of the CVI runtime that is needed for the application to work correctly. The end result is that it will upgrade the runtime in the target machines. It will not need to upgrade the CVI environment itself on the target machines.
Luis
NI