I know you're looking for something that somehow converts C# directly to PowerShell, but I thought this close enough to suggest it.
In PS v1 you can used a compiled .NET dll
PS> $client = new-object System.Net.Sockets.TcpClient
PS> $client.Connect($address, $port)
In PS v2 you can add C# code directly into PowerShell and use it without 'converting' using Add-Type (copied straight from msdn )
C:\PS>$source = @"
public class BasicTest
{
public static int Add(int a, int b)
{
return (a + b);
}
public int Multiply(int a, int b)
{
return (a * b);
}
}
"@
C:\PS> Add-Type -TypeDefinition $source
C:\PS> [BasicTest]::Add(4, 3)
C:\PS> $basicTestObject = New-Object BasicTest
C:\PS> $basicTestObject.Multiply(5, 2)