On the 144 MHz band, stations in Australia dont usually hear many other countries on tropo.

Is there any way, when we view the 144 MHz database, that we can set it to only bring up VK callsigns data ?
Ive tried just putting in VK and VK in the TX RX stations boxes, but that doesn't work.

Is there any trick to be able to do this or is it just not possible ?

Thanks