Nomad fail to do a volume_mount in windows container

Nomad
1

I have this config for client:

client {
host_volume “labmount” {
path = “\\pt-rnd-stg1\falcon_extract”
read_only = false
}
enabled = true
}

And here is my job configuration:

job “rm” {
datacenters = [“dc1”]

group “main” {
network {
port “rmaker” { static = 1947 }
}

volume “labmount” {
type = “host”
source = “labmount”
}

task "start-container" {
  driver = "docker"
volume_mount {
      volume      = "labmount"
      destination = "\\\\pt-rnd-stg1"
    }

  config {
    image   = "automation-lab-rm:0.0.1"
    command = "ping -t localhost > $null"
    ports = ["rmaker"]
    storage_opt = {
      size = "100G"
    }
  }

  resources {
    cpu    = 500
    memory = 2000
  } 	  
}

}
}

running job fails with error:
2023-01-26T13:03:43.850+0200 [ERROR] client.alloc_runner.task_runner: running driver failed: alloc_id=ce633104-ab62-8b76-7cfe-411e7b2f1c37 task=start-container error="failed to create container: API error (400): invalid mount config for type \"bind\": invalid mount path: '\\pt-rnd-stg1'"

NOTE: this i a windows container.
when I run nomad node status -self -verbose
I see

Host Volumes
Name ReadOnly Source
labmount false \\pt-rnd-stg1\falcon_extract