any ideas how to do it?

lets say that I have some long text in one database field, inside the text I have some 'tags' like %7 and %-7...now, when I display the text from this field(in php), eg echo $mydbarray["textcolumn"];, then it just displays 'mytext%7somemoretext%-7mytext'...but I want to echo the text between the 'tags' in some special way, in red for example. How? and if I had more than on pair of tags... so that the text between the tags will be displayed in some special way (EG %7 represents some css class) and all the other text would be displayed in the normal way... I hope you get what I need. From the first look it seems pretty easy, but when thinking about it...well, I couldn`t think of any possibilities:-) thanks Siim