Is there any way by which we can recover the Appian environment if the LDAP conn

Are you seeing any errors in your logs related to the LDAP connection failing? If so resolving these may fix your issue.

No the thing is I lost my previous LDAP server. I had to create a new server(which I did with the same name and same connection name)....i created the same users with the same userid....but seems like Appian is sensitive in the URL that I provided earlier to the LDAP and so I cannot recreate the same URL for my ldap server....and now I can't even login with administrator account. That also has been taken away. Is there any other solution other than creating a new appian instance with the kdb's....? I kind of vaguely know that a xml file in teh WEB.WAR/WEB-INF file consists of the URL and login credentials that I used when i did through admin console...but i can't seem to locate that one....any help would be deeply appreciated....

You can set conf.ldap.enabled to false in the cfg table and restart JBoss. You may then be able to use the internal passwords including the administrator account and reconfigure your ldap configuration.