http://wordpress.org/support/topic/plugin-jayj-quicktag-need-support-for-more-complex-tags

gistfile1.js

// A video button with parameters
QTags.VideoButton = function() {
	QTags.TagButton.call(this, 'Video', 'video', '', '', 'm' );
};
	
QTags.VideoButton.prototype = new QTags.TagButton();
QTags.VideoButton.prototype.callback = function(e, c, ed) {

	// The different parameters and their default value
	var src = prompt( 'Enter URL for video', 'http://' ),
	    width = prompt( 'Enter width for video', 640),
	    height = prompt( 'Enter height for video', 360 ),
	    thumbnail = prompt( 'Enter URL for thumbnail', 'http://' );
			
	if ( src && width && height ) {
		// Start start
		this.tagStart = '<video src="' + src + '" width="' + width + '" height="' + height + '">';
						
		// Add thumbnail
		if ( thumbnail )
			this.tagStart = this.tagStart + '<img src="' + thumbnail + '" alt="" />';
						
		// End tag
		this.tagStart = this.tagStart + '</video>';

		QTags.TagButton.prototype.callback.call(this, e, c, ed);
	}
};
			
edButtons[150] = new QTags.VideoButton(); // 150 is the position