In your component data, or within the design itself, you can specify text. If you put asterisks around a chunk of that text it will render using the alternate font. So here's some example text that you might write.
First they ignore you, *then they laugh at you*, then they fight you, *then you win*.
That would render like this (assuming you had your font and alternate font configured like the example). You can configure the alternate font under the "Advanced" section of the Add Text step.
If you need to actually put an asterisk in your text, then precede it with a slash like \*. Here's an example:
First they \*ignore\* you, *then they laugh at you*, then they fight you, *then you win*.
You can also use this feature to add graphical elements to your text, like adding icons inline with the text.