After I build my InstallShield I want to copy the outputted MSI file to some partocilar directory
..."\Documents\Visual Studio 2012\Projects\UpdateAppTest\Setup1\Setup1\Express\SingleImage\DiskImages\DISK1\setup1.msi"
to some directory on my computer

Did some more digging and came up with this...
InstallShield allows you to specify commands that can be run at various stages of the build process. These commands are called Build Events. This can be very useful, but in order to use this functionality, you must have the InstallShield Premier edition.
To define a Build Event, just go to the Releases view, click on a release, then click the Events tab. There you can define Prebuild, Precompressor and Postbuild events.
Source: http://www.installationdeveloper.com/2572/prebuild-and-postbuild-events-in-an-installshield-installation/