Yes it is possible.  What exactly are you trying to do?  Just give the CCM a public and Nat that?

thanks for your reply. are you sure that it will work. is there any document available ?

because I tried a different scenario. we have remote users using cisco IP communicator as soft phone . they are using cisco vpn client to connect to our CO and  their softphone is registering and can make calls via VPN. but  new company policy doesn't want to expose HO server lan  network ( including call manager IP ) to  vpn client users.

what I did is , in my  ASA FW ( VPN server )  i added a Nat configuration for  CCM , so in the softphone we have to mention the NATTED Ip . FOr testing I natted one to one with IP ( no restriction with any ports) .
but the issue is my phones are not registering, but it is  communicating to the CCM via NATTED IP and could download the configuration file .  registration is not sucessfull ,showing "Registering"

After some workaround I found that the configuration file that is downloaded to the softphone  from the  CCM is having the actual CCM IP  ( not the NATTED IP) . SO the phone is trying to register with the actual IP but  it is not reachable and eventually registration fails.

I did some sniffing and the capture reveals that Softphone is trying to reach the actual IP only,

see the image
in the Image you can see , SOFTphone is configured for 192.168.199.1 and 192.168.199.2 as tftp server , bu the downloaded configuration contains 10.71.x.x ( actual CCM IP) , also see the sniffer output.
IPC.jpg

is there any special configuration we need to do on the CCM ?.

You cannot register the any ip phone (Hard or Soft) to a natted CUCM IP.
But you casn always nat Phone subnet.

HTH

is there any document availbale saying that

what about device pool  ?

You need to enable SCCP proxy on the ASA (may require purchase of license)
http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008081042c.shtml#sccp