Other postings and articles don't explain where the entry is. Some even say to not modify this setting in the registry. I therefore do not know how to use DSC to change the password complexity policy setting. How do I use DSC to change the password complexity setting for local users?
you can use "net accounts" to manage the password complexity. For example the following will set the max password age to 50 days using script resource:
setscript = 'net accounts /maxpwage:50'. This link has more details.