Is this scenario possible?

hi, thanks for stopping by and taking time to help.

The Story:

i would like to use nextcloud to SHARE files with persons not having an account on my own nextcloud installation.
the FILES should be a SMB share within the same network.
i have configured users from LDAP, i created one group FC-USERS, and added so far two users.

it would be nice if ANY MEMBER of FC-USERS simply generates a document (PDF) and saves that to the common SMB share (\\somserver.local\fileshare\NEXTCLOUDFOLDER) then simply open his/her webbrowser to http://our.nextcloud.local/ and without signing in seeing the contents of the external storage/smb share so (s)he just has to right click the file, share it with a password set and copy the URL

is there a way to get single-sign-on running with the current active user (windowslogon / iexplore ) ?

so far everything is working, besides the “automatic login”