Param(
  [string]$source = "SourceFolder",
  [string]$dest ="\myshareSharedNetworkPath"
)
$Username = "Domainusername"
$Password = ConvertTo-SecureString "Password" -AsPlainText -Force

$cred = New-Object System.Management.Automation.PSCredential($Username,$password)

Copy-Item $source -Destination $dest -Recurse -ErrorAction SilentlyContinue -Credential $cred