(HELP) Wake On Lan over separate VLANs with different IP ranges.

I've been trying to get this to work for the past week...

The company I work for has a pretty large network which is divided into 4 separate VLANs, all with different IPv4 ranges.

The two imporant ones for this are these two.

1) 172.31.31.x (VLAN used for our office building)

2) 192.168.x.y (VLAN for the stores, where x is the store number and y is the host)

The stores are all equipped with a Saiwall slave router to be a part of our network.

Here's the head-scratcher... I want to set up a Wake On LAN system to be able to power on the store PCs to make it easier for us to solve issues, but I can't seem to get the magic packets to successfully transfer through the VLANs. Could anyone enlighten me?

One of the main issue I see here is that even though the stores are all in the same VLAN, they have different IPv4 ranges between them, since we use /24 mask on all devices... so it's tough to figure out which broadcast address would be correct for WOL, or if it's firewall issues.

For reference, while setting up new store PCs, I was able to test WOL within our office VLAN, so the Wake On LAN settings on the hosts themselves are fine.