Now, we are getting a little fancy
Add a Custom Table resource. For the data source selection, change the first drop down to 'Advanced Database query (SQL, SWQL)' and switch the radio button to 'SQL' when it shows up
The below SQL should work (Change the 2 items in orange - x.x.x.x to your SolarWinds server IP. Change the AlertDefID for it from the AlertDefinitions table in the database)
SELECT Nodes.Caption, Nodes.StatusLed, AlertStatus.TriggerTimestamp, ('<a href="'+'http://x.x.x.x/Orion/Netperfmon/AckAlert.aspx?AlertDefID=462c2d7e-33da-4717-85aa-fd77157e9bb0:'+ CAST(Nodes.NodeID AS VARCHAR) +':Node' + '">Click to Ack<a/>') AS URL
FROM (AlertDefinitions INNER JOIN AlertStatus ON (AlertDefinitions.AlertDefid = AlertStatus.AlertDefID) INNER JOIN nodes ON (AlertStatus.ActiveObject = Nodes.Nodeid)) WHERE AlertStatus.Acknowledged=0
when you choose the columns, be sure to check the 'Allow HTML tags' for the URL column
Credits: Query adapted from Active Alerts for Advanced Alerts - replace "All triggered alerts" on summary