Special characters like the swashes in Bulletto and Hello Script, or the alternates in Coco Gothic, use open type technology to substitute character sequences with special glyphs. Not all existing software  support OpenType (notably Silhouette Studio).You can check the software that works with standard open type ligatures here:

Microsoft Word users be aware that Open Type works in Word only since Word 2010. To enable OpenType ligatures, right-click on some text, select Font, select the Advanced tab, and selectStandard Only from the Ligatures combo box. This enables the standard ligatures, that we use for extra glyphs in all our open-type enhanced fonts.

For some of our typeface we provide a "compatibility pack" with only the extra characters and swashes, so that you can type them in any software - but generally if you need to use special characters within a software that doesn't support Opentype, the best option is to generate your designs with some open type enabled software and then export a vector or bitmap image you can work with.