Sending a single weird packet

[sunny sunny]

Hi,

I know this might sound a bit weird, but I want to send a packet which
is a bit different from the normal hostap packets.

I have a laptop working as AP using the hostAP drivers (ver 0.0.4).
During its normal operation I need to send a single packet which will:

1. Be transmitted at a different power
2. To a client that is not associated
3. At a different channel 

During the transmission of this single packet the clients connected to
the AP should not be affected (so I cant use it to make the interface
in ad-hoc mode and then back to master mode). Here is where I am now:

1. Transmitting at different power: This list has helped me figure out
that the way to do this would be to use 'iwpriv' and set the tx power.
But this results in beacon frames etc being generated which notify all
the clients that the AP power has changed. Dont want that to happen.

2. Sending msg to a non-associated client. I try to set the arp table
for this and disable arp from the interface on which hostAP is
running. But hostAP refuses to send the packet out saying that it
cannot send the packet to a station not associated with it. I am
thinking of looking up and adding this station to some associated
station list (still have to find this) and then remove it. Can I do
this ? Is there a better approach ?

3. Sending on different channel. I understand that to do this the only
way would be to change the channel using iwconfig?

Other thoughts: 
Is there some easy way out of all this? Like setup a VLAN ? or send
the message using some kind of inter AP protocol (the receiver is not
an AP but I can change that if required)..

Thanks for your help. Any pointers are helpful.
Santosh