Your rule should work fine. Just append ?
at the end of target URI to strip off existing query string:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www\.)?domain1\.com$ [NC]
RewriteCond %{QUERY_STRING} ^Itemid=230$ [NC]
RewriteRule ^$ http://domain2.com/temoporary-solution.html? [R=302,L]