http://www.gfi.com/blog/windows-powershell-extract ing-strings-using-regular-expressions/

a celkem to i funguje

$input_path = '.\example.txt'
$regex = '([a-zA-Z]{3,})://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)*?'
Select-String -Path $input_path -Pattern $regex -AllMatches |%{$_.matches} |%{$_.value}

http://www.adresa.cz
http://www.adresab.de


.. bude to chtít upravit REGEX aby to vzalo kompletní URL .. a ne jen domenu :)

Edit:

$regex = "(http|ftp|https):\/\/([\w\-_]+(?:(?:\.[\w\-_]+)+) )([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#] )?" by mělo stačit