DHCP -> how to assign different ranges (e.g. according to vendor class)

[longtom]

When i use the DHCP Server in opnsense how do i use the different ranges?
e.g. 192.168.1.0/24 2 DHCP ranges (100-149, 150-159).
I want that only some clients with a specific vendor ID gets the 150-159 address.

Is there any way to do that?
If not, how can i assign users in the additional range of 150-159?
I don't understand the logic when this address-range is taken.