Maybe try this:
Code:
Shell 'cmd /c "\\s-netstorage\OfflineMigrationLog$$\Tools\csccmd.exe"'
		+' /moveshare:"\\' + $OLDSERVERNAME + '\' + $SHARENAME +'\' + @USERID +'"'
		+' "\\' + $NEWSERVERNAME + '\' + $SHARENAME + '\' + @USERID + '"'