How to bind to different parts of your organisation

[mabels]

hello,

i have some users in diffrent parts of the directory structure like:

CN={user.name},OU=administratoren,DC=ad,DC=wurst,DC=net
or
CN={user.name},OU=users,DC=ad,DC=wurst,DC=net

and to bind them need the full dn. Is there any hint how to prebind and than search for the user and
bind the found user?.
This schema is for example used in the ldap adapter for openvpn. There i have a prebind user and later define a SearchFilter "(&(sAMAccountName=%u))"

Is this pattern implemented?

thx

meno