How can I check password complexity?

I am using PowerShell to create local users. I need to get input from keyboard: Username & Password. To get the password I can use one of the following:

$user_details = Get-Credential

or

$pass = Read-Host -assecureString "Please enter your password"

In both cases, I will get encrypted password variable System.Security.SecureString. In both cases, when I try to create the user, with

New-LocalUser -Name $username -Password $pass

I get an error that the password is not complex.

New-LocalUser : Unable to update the password. The value provided for the new password does not meet the length, complexity, or history requirements of the domain."

Since the password is encrypted, (System.Security.SecureString) I have no way to know the complexity of the password. How can I force the user to type a password that complies the complexity rules?

(using unencrypted passwords is not a good solution for me)

Update: After few answers that were relevant with good solutions, but did not meet my security requirement, I'd like to rephrase:

How can I check password complexity which is already stored in object: System.Security.SecureString (without decryption)