Loading certificate from a program each request?

I tried with:
SSLCertificateFile '|/etc/httpd/fetchcert %{SERVER_ADDR}'
and
SSLCertificateFile 'exec:/etc/httpd/fetchcert %{SERVER_ADDR}'
but it didnt work.

fetchcert is a executeable.

The apache server is a proxy. When a reqest arrives, the apache will
put the target ip of that packet into %{SERVER_ADDR}. The purpose of
this configuration is that the fetchcert software,will connect to that
server, and then fetch the certificate from that server, and then
resign it using OpenSSL and then deliver it on STDOUT.

If theres no solution, why cannot apache then implement this in
mod_ssl since this would be useful in enviroments, where the Apache
machine holds say about 50 customers, with 50 different IP adresses,
and each customer has a own certificate that is posted in a database
or somewhere, and each host has its own directory using a rewriterule.

And it would be useful in some proxy enviroments where a administrator
needs to proxy and resign certificates for a couple of servers where
the administrator dosent have control of.

And this is technically possible. Its only multiple certificates per
one IP that isnt possible.