I would like to know if its possible in a SPS2003 to run a manually
written script as batch file to add a list of defined custom site
groups in a site and also if possible all the already defined
permissions for each library in the site...

to represent my need, I would like something like that in a .bat file
and this run manually when needed:

c:\stsadm -o addSiteGroup -siteGroupName1 mySite -permissions
myPermList -url mySiteURL
c:\stsadm -o addSiteGroup -siteGroupName2 mySite -permissions
myPermList -url mySiteURL

c:\stsadm -o giveSiteGroupPermissions -siteGroup mySiteGroupName1 -
documentlibrary myLibrary -permissions myPermissionsList

etc...

I saw that stsadm could not resolve this but does any other tool
(or .Net progs) could be?