Controlling connected Access Point through DeviceIoControl on Vista

Hi,

I want to be able to scan for the best access point, and control connection
programatically. I need to do this to improve the handover time whilst
streaming live audio/video.

I am trying to do this by using two wireless adapters, one to do the
streaming and the second to continuously scan for the best AP, and when I
determine there is a better AP to use I can get the streaming adapter to
disconnect/reconnect.

I have this working on XP using NDISUIO. However on Vista the call to start
the scan fails with error code 1008 (0x3F0). ERROR_INVALID_TOKEN.

I've tried changing the code to use the NDIS 6 OIDs, but with no success. I
can't find
IOCTL_NDISUIO_QUERY_OID_VALUE in the Vista DDK, so it appears that
Microsoft don't support this route and want me to use the Native WiFi API
instead. However I can't find any way of disabling scanning on one of the
adapters using the Native WiFi API.

NDIS 6 seems to allow setting a "Media Streaming" mode which disables
scanning. This is clearly what I need to use.

Can anyone tell me how to do this?
Thanks
John.