Not entirely sure if this would be the answer your looking for, but I use this report to send me emails whenever a new device shows up on my network.
New assets seen in the past hour
Select Top (1000000) tsysAssetTypes.AssetTypeIcon10 As icon,
  tblAssets.AssetID,
  tblAssets.AssetName,
  tblAssets.Domain,
  tblAssets.Username,
  tblAssets.Userdomain,
  tsysAssetTypes.AssetTypename As Type,
  tblAssets.IPAddress,
  tblAssets.Description,
  tblAssetCustom.Manufacturer,
  tblAssetCustom.Model,
  tblAssetCustom.Location,
  tsysIPLocations.IPLocation,
  tblAssets.Firstseen As [Created at],
  tblAssets.Lastseen As [Last successful scan]
From tblAssetCustom
  Inner Join tblAssets On tblAssetCustom.AssetID = tblAssets.AssetID
  Inner Join tsysAssetTypes On tblAssets.Assettype = tsysAssetTypes.AssetType
  Left Outer Join tsysIPLocations On tsysIPLocations.LocationID =
      tblAssets.LocationID
Where tblAssets.Firstseen > GetDate() - 1 And tblAssets.Firstseen >
  DateAdd(HOUR, -1, GetDate()) And tblAssetCustom.State = 1 And
  tblAssets.Assettype <> -1 And tblAssets.Assettype <> 66
Order By tblAssets.AssetName
Then in my E-mail/Export reports section I added this highlighted section to get the reports straight in my inbox.

Result looks like this:

Hope this helps.