HG3-Include is a plugin by Gerard Ceccaldi that allows you to include any code (html, php, javascript,…) directly into the WordPress editor.
Based on ‘MaGiKS Proper PHP’, a plugin from Keith James Lock, ‘HG3 Include Codes’ allow you to include any code (html, php, javascript,etc.) directly into the WordPress editor. Syntax near to PHP, you can now precise the path of the file to include using real path, relative path or using a CONSTANT. A query (myfile?a=1) and a variable can also be sent to the called file.
Download: http://wordpress.org/extend/plugins/hg3-include/