HTML column in a full text index?
From at least SQL Server 2008 R2 SQL Server comes with an understanding of HTML.

http://msdn.microsoft.com/en-us/library/ms142499.aspx says: "
SQL Server installs its own XML and HTML filters. In addition, any filters for Microsoft proprietary formats (.doc, .xdoc, .ppt and so on) that are already installed on the operating system are also loaded by  SQL Server."

You mention umlauts, but not what you want to do with them.  Umlauts and other characters that may seem unusual to English readers, can be managed by choosing the proper collation for the Index. Also the chosen Word Breaker (Neutral, English, French, etc) will affect your results.