Cisco WAN :: 1841 - NAT Configuration

I have a little problem configuring NAT on router 1841, like this is the topology:
 
 
                    WAN (PUBLIC´S ADDRESS)   fast0/0        fast0/0/0                PUBLIC´S ADDRESS                        INSIDE (192.168.1.0/24)
ROUTER ====== X.X.X.X/30============= ROUTER ======== Z.Z.Z.Z/29 ============ SW 3560==============
  (ISP)      .253                                         .254 CLIENT  . 47                                                .48    
 
 
The connection with ISP or Extra net is a metro Ethernet, so the isp gave two ip address to the client: WAN (/30)
LAN (/29) Which be the public addresses to be used by the client if you need to publish any server on the network (like WWW), so they do not have any device that will could do the nat, like an asa or linux server, so the router has to do the Nat, because the SW 3560 does not support this feature.
 
 So... I did the following:
 
On router 1841:
 inter fast 0/0
description WAN
no shut
[ code ]... 
 
I create an interface Blackpool to simulate the LAN connection (192.168.1.0/24)
 
Inter loopb 0
ip address 192.168.1.254 255.255.255.0
ip nat inside
 [ code ] ...
 
ON SWITCH:
 
interface vlan 448
description LAN-ME
ip address Z.Z.Z.48 255.255.255.248
no shut
 ip route 0.0.0.0 0.0.0.0 Z.Z.Z.47
  
But if i try to do ping from the ip address 192.168.1.0/24 to any server´s internet the ping fails, but if i do the ping from v LAN 228 the ping is success. I will think that route map could solve the problem.