Reverse Proxy: Capture error pages and serve generic error page from proxy

Reverse Proxy: Capture error pages and serve generic error page from proxy

Architecture :
Client
|
v
SSL/HTTP
|
v
HAProxy 1.5-dev12
|
v
Apache 2.4 mod_proxy
|
v
Backend Web Apps
Is it possible, with HAProxy to intercept a error response code and serve
an error page from HAproxy ?
Config:
errorfile 400 /var/www/MASKEDco.zw/errors/400.html
errorfile 403 /var/www/MASKEDco.zw/errors/403.html
errorfile 408 /var/www/MASKEDco.zw/errors/408.html
errorfile 500 /var/www/MASKEDco.zw/errors/500.html
errorfile 502 /var/www/MASKEDco.zw/errors/502.html
errorfile 503 /var/www/MASKEDco.zw/errors/503.html
errorfile 504 /var/www/MASKEDco.zw/errors/504.html
Basically I'm trying to achieve a unified feel across all web apps,
without having to rely on the developers to point their redirects to the
correct url's.
Anyone got any ideas?
Thanks!