The New-CFNStack cmdlet lets you submit the template to create the stack. If there are any property issues at any stage of the operation, it will roll back the whole stack. Otherwise, you should get a CREATE COMPLETE message in the stack events. In this case, you can also make use of the TemplateURL switch if your template is available in S3. In the template created, you have five input variables. You can define the values of those input variables by creating the new object using class Amazon.CloudFormation.Model.Parameter.
$vpcstack=(Get-Content -Raw D:\scripts\basenetwork.txt)
$p1 = New-Object -Type Amazon.CloudFormation.Model.Parameter
$p1.ParameterKey = "VPCCIDRRange"
$p1.ParameterValue = "10.12.0.0/16"
$p2 = New-Object -Type Amazon.CloudFormation.Model.Parameter
$p2.ParameterKey = "PublicSubnetCIDR1"
$p2.ParameterValue...