Changing a password through extended operations

Hello,
I'm trying to figure out if I can change a users password through the LDAP 
APIs through it's extended operation.
It looks like it can be done through RFC3062 LDAP Password Modify Extended 
Operation (http://www.ietf.org/rfc/rfc3062.txt), but I'm not sure if the 
client API supports that RFC.

I've seen a few examples using the command line tools, but I want to be able 
to do it from an LDAP C++ client application, using the old password for 
validation and updating the entry with the new password.  From the RFC, one 
would perform an extended operation with OID 1.3.6.1.4.1.4203.1.11.1 and 3 
data elements userIdentity, oldPassword, and newPassword, but the 
ldap_extended_operation and ldap_extended_operation_s APIs only take a 
pointer to a berval structure.  Berval structures only contain a data length 
and a char*, so unless the 3 parameters are encoded some out it's not going 
to work.

Anyone know if and/or how this works from the API?

Thanks,
Jim