This is the one I used...

StartupLoader default executeAtomicItems: {
� �StartupAction name: 'Shared Package Cache' code:
� �[ � MCCacheRepository default directory setPathName: 'C:\Smalltalk\#Shared-Package-Cache'.
� � � �MCDirectoryRepository defaultDirectoryName: 'C:\Smalltalk\#Shared-Package-Cache'.
� �].
}.

I'm not sure of the function of the fourth line (I copied it from http://marianopeck.wordpress.com/2012/05/12/startuploader-running-startup-scripts-in-pharo/)