Foren / Cotonti / Extensions / Automatic Welcome PM after registration

hm.Add a input field in the setup file.Something like:

[BEGIN_SED_EXTPLUGIN_CONFIG]
Message=08:string:::Additional pages fields for search, separated by commas. Example "page_extra1,page_extra2,page_key"
[END_SED_EXTPLUGIN_CONFIG]

and then in welcomepm.en.lang.php add something like this:

$L['plu_pmtext']  =  $Message

I really cant remember how exactly to do this.Coders please correct me