In case you don't want to work with PowerShell then here's a pure batch solution How to Generate a Secure Random Password using PowerShell.Generating a New Password with Windows PowerShell.There are several MS TechNet blog posts on this:
For example to generated a 12-character long password with at least 3 special symbols you can call it like this # Just need to call once at the start of the script With PowerShell you have another better option: call GeneratePassword(int length, int numberOfNonAlphanumericCharacters). Of course if security is not a concern then echo %random%%random% in cmd or Get-Random -Minimum 100000000 in PowerShell will just work Depends on how strong you want your password to be.
