Hello Cristina Vega,
In order to achieve the desired functionality follow these steps.
1. Add the following code to the respective ListConfigFile.xml, which is located in the /Program Files/Common Files/Microsoft Shared/web server extensions/wpresources/RadEditorSharePoint/4.x.x.x__1f131a624888eeed/RadControls/Editor folder.
oValue = editor.GetHtml(
'insert here the info regarding this'
I hope this helps.
the Telerik team