I think NPS (Network Policy Server / RADIUS) is capable of doing this, however, I'm not sure if it is possible trough VPN:
http://technet.microsoft.com/en-us/library/cc754422(WS.10).aspx
VLAN Attributes Used in Network Policy
VLAN attributes used in network policy
When you use network hardware, such as routers, switches, and access
controllers that support virtual local area networks (VLANs), you can
configure Network Policy Server (NPS) network policy to instruct the
access servers to place members of Active Directory® groups on VLANs.
Before configuring network policy in NPS for VLANs, create groups of
users in Active Directory Domain Services (AD DS) that you want to
assign to specific VLANs. Then when you run the New Network Policy
wizard, add the Active Directory group as a condition of the network
policy.
You can create a separate network policy for each group that you want
to assign to a VLAN. For more information, see Create a Group for a
Network Policy.
When you configure network policy for use with VLANs, you must
configure the RADIUS standard attributes Tunnel-Medium-Type,
Tunnel-Pvt-Group-ID, and Tunnel-Type. Some hardware vendors also
require the use of the RADIUS standard attribute Tunnel-Tag.
To configure these attributes in a network policy, use the New Network
Policy wizard to create a network policy. You can add the attributes
to the network policy settings while running the wizard or after you
have successfully created a policy with the wizard.
Note
- To add the attributes after you have created the network policy with
the wizard, locate the policy in the NPS console and double-click the
policy to open it. Click the Settings tab in the policy properties,
ensure that RADIUS Attributes - Standard is selected, and then click
Add. In the Add Attribute dialog box, add the following attributes.
Tunnel-Medium-Type. Select a value appropriate to the previous
selections you made while running the New Network Policy wizard. For
example, if the network policy you are configuring is a wireless
policy, in Attribute Value, select 802 (Includes all 802 media plus
Ethernet canonical format).
Tunnel-Pvt-Group-ID. Enter the integer that represents the VLAN number
to which group members will be assigned. For example, if you want to
create a Sales VLAN for your sales team by assigning team members to
VLAN 4, type the number 4.
Tunnel-Type. Select the value Virtual LANs (VLAN).
Tunnel-Tag. Some hardware devices do not require this attribute. If
your hardware device requires this attribute, obtain this value from
your hardware documentation.