Extract parameters from a message

Hello @vasek thanks for your quick response,
The problem is that this parameter isn't always at the same place,

DialedNumber=000000000&ID=843&CountryCode=00&AreaCode=33&Tenant=2002&AgentID=0&GroupID=0&ScriptSource=1&AgentLeg=0

Also in some lines the Tenant doesn't exist at all