Oui bien sûr :).
You go to your dashboard --> Settings --> Layout --> Page Elements. Here you’ll see your blog’s page where you can drag and drop elements to change their places. Simply click on “add a page element” in the top corner of your sidebar and choose HTML/Java script, since you’re adding a widget. Click on "add to blog’ and you will get a window where you should insert your piece of HTML code and a title if you wish.
Save it, and you’re done.
Don’t forget to click on save also in the top corner of your ‘page elements’ to see the change on your blog.
Ha! J’avais mon dashboard en anglais ^_^.