Celeste,
there are different ways to modify the appearance of the module, but first: the Captcha is as it is (at the moment). The Submit button is either a link or a button (at the moment) - you can choose that from the settings.
First: There is the possibility for theming. You should be a bit exprienced in CSS, and have a look at the "fancy" theme - it explains quite everything that's possible by "doing" it, that's what it's thought for (I hope no one will use this theme on a production web site, it's only a show case/kind of a tutorial and quite "ugly"). Just copy the folder to another folder under /DesktopModules/helferlein_Form/Themes, e.g. "MyThemes", and rename the .css file the same way (eg. "MyTheme.css"). You can then choos "MyTheme" from the settings. Modify the css file the way you want.
Second: Templates. See the help section here how to use it.
Thanks for using the module...
Michael