Yes you can have a single physical interface on the host, create a vSwitch for each VLAN (Internal & External) and assign them to the relevant vNICS on the Expressway-E (or VCS-E).
Just need to note that you may need to add static routes to the DMZ expressway so it can access your internal network (VCS Control/ExpresswayC, DNS, NTP, etc) , example below
xconfig IP Route 1 address: "10.0.0.0"
xconfig IP Route 1 prefixlength: 8
xconfig IP Route 1 gateway: "10.1.1.1"
xconfig IP Route 1 interface: LAN2 (or LAN1 if that is your internal)
xconfig IP Route 2 address: "172.16.0.0"
xconfig IP Route 2 prefixlength: 16
xconfig IP Route 2 gateway: "10.1.1.1"
xconfig IP Route 2 interface: LAN2 (or LAN1 if that is your internal)
To make things a bit more secure is if you have a DMZ switch, look at setting private VLANs set a private VLAN for two separate ports and connect them to two separate ASA ports. Then have a Dot1Q to the host.
good luck!, please rate helpful posts.