I'm not sure if I understand the question correctly... if you have 1:1 nat, then the users can connect to 192.38.X.X port 443 which gets translated to 10.100.x.x port 443, and they can connect to 192.38.X.X port 444 which gets translated to 10.100.x.x port 444, etc.
If you want all sites to be on port 443, then you'll need different ip addresses for each site.
static (dmz,outside) 192.38.X.1 443 10.100.x.x 443
static (dmz,outside) 192.38.X.2 443 10.100.x.x 444
static (dmz,outside) 192.38.X.3 443 10.100.x.x 445
etc.
Using the same public ip and same port for all sites is not possible, since the only distinction is in the HTTP headers, which are invisible (encrypted) for the FW.
hth
Herbert