Meta tag on text

Hi,

Well, I'm using the simple example that comes with the tlf and now I'm making some customizations. Something that I'm need to do is to put some metatags on my text. For example, when the user type [sound:asdfas.mp3] i would like to mark  this text with diferent style. Or, in some cases, the user can use variables on my text, for example [var;income] so, when the user choice to print the text, i replace this variable for a current value.

Anyone has any ideia of how can I do it?

Thanks.