I need to pass LDAP credentials to a web-service to authenticate in C#.

I've got everything setup to get the user using DirectoryEntry, however, for obvious reasons I can't get the password.

I authenticate to a third-party web service in C# by passing the username/password like: `j_username=me%40domain.com&j_password=mypassword%21`

I know getting the LDAP password is impossible but is there a better way to go about what I'm doing?