It sounds like it might be possible, but not so easy as just being able to send a single line and simple GET HTTP Request.
Looking on Google quickly there looks to be several ways to go about doing this. There are various projects on Github for controlling Wemo devices, that use solutions like node.js, python, groovy, these I assume would need an always ON middle man box to relay the commands to the Wemo devices.
Or it sounds like it might be possible to send commands directly to the Wemo devices, but not sure about authentication if that would also be involved in some way? Sounds like you can possibly send HTTP POST commands with SOAP headers to control the Wemo devices.
How many Wemo devices do you have? Might be more trouble than its worth.
Also looks like there was a Vera Wemo plugin in the past, have you ever used that at all ?
First thing if attempting sending direct commands would be to get those commands working first in the command line terminal before even attempting to then integrate them with Vera / Ezlo.
Search this forum also as there was some past talk about it like here.
Also it sounds like the Wemo devices can change their port numbers so that makes it harder also, you would likely need to put your commands in to a script and run that from the Vera / Ezlo hub maybe tied in with a virtual switch.
This post on the OpenHab forum talks about the port numbers changing here