As others have mentioned, to have a Windows DHCP server issue DHCP leases from two separate /24 scopes, you would want to implement VLANs. I don't recommend using a superscope unless absolutely necessary. It just gets ugly.
For VLANning, you would need a managed switch that handles VLAN tagging. You would want to tag traffic for a given port as belonging to VLAN 2 or 3 (just example VLAN IDs - you can choose whatever you want aside from VLAN 1, as that is the default VLAN).
To do so, first you would configure VLAN 2 and 3 in the switch with an IP address in either DHCP scope. For example, VLAN 2 has 192.168.1.253, and VLAN 3 has 192.168.2.253.
Then, you want to tag each given switch port as belonging to either VLAN. In most switches, this is done with a command similar to
switchport access vlan 2. Substitute 2 for 3 where desired.
After this, configure each VLAN with an IP helper address of the DHCP server. IP helper tells traffic where to go to get a DHCP lease, but tags the traffic for that specified VLAN, and makes the request appear to come from the VLAN IP address. So the server would see the DHCP request coming from either 192.168.1.253, or 192.168.2.253, and issue a DHCP lease in whichever subnet the request came from.
All of this working together would allow you to get a DHCP lease from the desired scope.