Okay...
[code]rewrite ^/cat([0-9]*)\.htm$ index.php?c=$1;
rewrite ^/(forum|.*-vf)([0-9]+)-([0-9]+),([0-9]+)\.htm$ viewforum.php?f=$2&topicdays=$3&start=$4;
rewrite ^/(forum|.*-vf)([0-9]+),([0-9]+)\.htm$ viewforum.php?f=$2&start=$3;
rewrite ^/(forum|.*-vf)([0-9]+)\.htm$ viewforum.php?f=$2;
rewrite ^/prev_topic/([0-9]+)\.htm$ viewtopic.php?t=$1&view=previous;
rewrite ^/next_topic/([0-9]+)\.htm$ viewtopic.php?t=$1&view=next;
rewrite ^/(topics[0-9]*/)?(.*-vt)?([0-9]+)-([0-9]+)-([a-zA-Z]+),([0-9]+)\.htm$ viewtopic.php?t=$3&postdays=$4&postorder=$5&start=$6;
rewrite ^/(topics[0-9]*/)?(.*-vt)?([0-9]+)-([0-9]+)-([a-zA-Z]+)-([a-zA-Z0-9]+),([0-9]+)\.htm$ viewtopic.php?t=$3&start=$7&postdays=$4&postorder=$5&highlight=$6;
rewrite ^/(topics[0-9]*/)?(.*-vt)?([0-9]+),([0-9]+)\.htm$ viewtopic.php?t=$3&start=$4;
rewrite ^/(topics[0-9]*/)?(.*-vt)?([0-9]+)\.htm$ viewtopic.php?t=$3;
rewrite ^/postlink/([0-9]+)\.htm$ viewtopic.php?p=$1;
rewrite ^/search\.htm/authors/(.+),([0-9]+)$ search.php?search_author=$1&start=$2;
rewrite ^/search\.htm/([0-9a-z]+),([0-9]+)$ search.php?search_id=$1&start=$2;
rewrite ^/search\.htm/([0-9a-z]+)$ search.php?search_id=$1;
rewrite ^/members/([a-z]+)_([a-z]*)-([A-Za-z]+),([0-9]+)\.htm$ memberlist.php?letter=$2&mode=$1&order=$3&start=$4;
rewrite ^/members(\.htm|/?)$ memberlist.php;
rewrite ^/profiles/([0-9]+)\.htm$ profile.php?mode=viewprofile&u=$1;
rewrite ^/groups/?([0-9]*)(\.htm)?$ groupcp.php?g=$1;
rewrite ^/groups/?$ groupcp.php;
rewrite ^/sitemap,([0-9]+)\.htm$ sitemap.php?offset=$1;
rewrite ^/topics([0-9]+)/?$ viewforum.php?f=$1.htm;
rewrite ^/(topics|postlink|prev_topic|next_topic)/?$ index.php;
rewrite ^/profiles/?$ memberlist.php;
rewrite ^/(.+)\.htm(\?.*)? /$1.php$2;
rewrite ^/(.+)\.php(\?.*)? /$1.htm$2;
[/code]

But I dont know how translate RewriteCond?

And this rewrite dont working in 100%.
http://www.landwirtschafts.net/cat4.htm - working
http://www.landwirtschafts.net/portal.htm - dont working
http://www.landwirtschafts.net/index.htm - dont working
http://www.landwirtschafts.net/members.htm - dont working

How to fix it?