Dynamic Vlan Allocation based on LDAP Attribute Value

I have a working radius server (ver 1.1.3). which I am using for 802.1x authentication of wired switch ports. I would like to dynamically assign users vlans. I have cisco gear and have achieved basic vlan allocation by configuring a Default entry in the users file. So the vlan allocation part works ok. What I want to be able to do is allocate the vlan by matching the value of an LDAP attribute. Not by group membership, but the actual value of a users attribute. Is this possible? Cheers, Dealy