Attach my Own webservice for spell Check in SharePoint

I want to attach my own web service for spell check in SharePoint. How can i attach my own web service. Or is there any other way in which i can attach it SharePoint.

Like i have to add it to SharePoint Task list in which we have options like Spelling to find incorrect spelling. i want to do with my custom button with my web server.

Please suggest me so way to that.