Hi Srinivasan!
Identification can be done using descriptive programming.
Here is example # 1 with description object.
set EditDesc = Description.Create()
EditDesc("Name").Value = "userName"
EditDesc("Index").Value = "0"
Browser("Welcome: Mercury").Page("Welcome: Mercury").WebEdit
(EditDesc).Set "MyName" 
Here is example # 2 with out description object.
Dialog("text:=Login").WinEdit("window id:=3001","attached 
text:=Agent.*").Set "john"
Dialog("text:=Login").WinEdit("window id:=2000","attached 
text:=Password:").Set "mercury"
Dialog("text:=Login").WinButton("text:=OK").Click
These both method will be used in expert view to identify 
object with out object avaialble in object repository.