Hi
Looks like you can achieve the required functionality by using below properties specified portal-ext.properties file -
1##
2## Default User Public Layouts
3##
4
5 #
6 # If the properties "layout.user.public.layouts.enabled" and
7 # "layout.user.public.layouts.auto.create" are both set to true, then users
8 # will have public layouts and they will be automatically created. The
9 # settings below are used for the creation of the initial public pages.
10 #
11 # If you need to add more than one page, set the property
12 # "default.user.public.layouts.lar" to specifiy a LAR file instead.
13 #
14 # For even more complex behavior, override the addDefaultUserPublicLayouts
15 # method in com.liferay.portal.events.ServicePreAction.
16 #
17
18 #
19 # Set the name of the public layout.
20 #
21 default.user.public.layout.name=Welcome
22
23 #
24 # Set the layout template id of the public layout.
25 #
26 default.user.public.layout.template.id=2_columns_ii
27
28 #
29 # Set the portlet ids for the columns specified in the layout template.
30 #
31 default.user.public.layout.column-1=82,3
32 default.user.public.layout.column-2=33
33 default.user.public.layout.column-3=
34 default.user.public.layout.column-4=
35
36 #
37 # Set the friendly url of the public layout.
38 #
39 default.user.public.layout.friendly.url=/home
40
41 #
HTH