Selecting The First 500 Characters Of A String With HTML Formatting Without Eliminating The Closing Tags.

Hello Forum,
I've got a column that displays text, from a sql table, in a label.  Some of the rows have HTML tags that format them.  I want to display only the first five hundred characters of the text and hide the rest but this means, for rows with HTML formatting that have more than 500 characters, the tags aren't closing which ruins my formatting.
How can I hide some of my text without leaving my HTML tags unclosed?
Thank you
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