remote using .\Administrator

Hey Guys,

I read the Month of Lunches book and now putting it to use.  

I need to check the DNS server list on my server.  So I'm using the Invoke-command and trying to login as the local administrator.

Invoke-Command -Computer Server01 -Credential .\Administrator -ScriptBlock {get-process}

Invoke-Command -Computer Server01 -Credential Server01\Administrator -ScriptBlock {get-process}

The 2 examples above do not work.  A domain login works fine.  But I must use the local Administrator account.

Thanks
Jim