1. Probably, depends on what you're using CNA for. List what you want the software to do and we can probably help out (how many devices too).
2. You can use an ACL to determine which hosts can connect via HTTP or not.
ip http access-class ?
<1-99> Access list number
Let's use ACL number 50.
ip http access-class 50
access-list 50 permit 192.168.1.5
aceess-list 50 permit 192.168.1.6
This would allow only .5 and .6 to connect to the router via HTTP.
HTH and please rate.