Hi,
In documentation mentioned as a remarks for "BaseToolbarItem" class as
=>Only items which derive from BaseToolbarItem can be added to the toolbar.
Ref:-http://help.infragistics.com/Help/NetAdvantage/ASPNET/2011.1/CLR4.0/html/Infragistics4.WebUI.WebHtmlEditor.v11.1~Infragistics.WebUI.WebHtmlEditor.BaseToolbarItem.html
So,
Hi chittaranjan,
It has been some time since your post, however in case you still need assistance I would be glad to help.
As far as I can understand you wish to know whether custom items may be added to WebHtmlEditor's toolbar. One way to achieve this would be thorugh the editor's designer:
QuickDesing -> Toolbar -> Add -> Add Custom Item
Please feel free to contact me if you have any questions.