I would be very glad if anyone can give me a good solution the below problem..

I have a domain abc.com (internal – IP 192.169.1.0 range) which was nated from a public IP say 10.10.10.1 . My external users use my public IP to access some citrix applications.

Now I want to install SSL setup for my Citrix applications. For that I am going to purchase another external domain – say xyz.com. After this my external users will access the application like www.xyz.com/citrix..

So here, I need to know how I can point the DNS of new domain xyz.com to my external IP (10.10.10.1) . Also I would like to know is there any changes to be done on my internal domain DNS

In case, If I am making my internal domain abc.com into SSL by using MS Certificate or Verizon certificate, instead of buying a new domain.. whether the external users can access the application using the same public IP in a SSL mode..Pls. clarify.

Regards,
Anand

Think you have this backwards; all 10.*.*.* are private, non-routable class A addresses.
Your 192.169.*.* is a public class C address

Your SSL Cert needs to be bound to the Public address.

I just mentioned two IPS to understand the scenario..If you consider that my Public IP canot be routed..take 80.220.* * as my public IP..the other on is as I mentioned Internal one - 192.168.*.* ..Can u suggest how I can implement the SSL ..

You're going to need to be able to configure your webserver
(Whiich one are you using?)
Load the SSL library code (Google for OpenSSL)
and generate or purchase a certificate.

On this last point, see your webserver documentaion.