If you insert the <input> element manually you won't be able to get its value easily on the server side - it won't be mapped automatically to a server-side control because it doesn't exist.
You should be able to read the values during PostBacks using Request.Form[name]:
string value = Request.Form["inputname"];
If the purpose of inserting the <input> is to allow editing the resource, I suggest you take a look at the active areas feature introduced in 7.1:
http://www.daypilot.org/demo/Scheduler/ActiveAreas.aspx
It allows you to add a hover icon that will activate a context menu (or fire custom JavaScript).