PowerShell access parameter value passed

Question

I am running a external program on SolarWinds which calls PowerShell script and i am passing hostname as a parameter to my script .

param( $hostname )

$hostname1 ="$($hostname)"

$hostname1 |Out-File D:\hostname.txt

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output in hostname.txt is

${N=SwisEntity;M=F5Device.Node.DisplayName}

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how can i get the value of hostname (value of F5Device.Node.DisplayName ) ..?