Is it possible to configure captive portal for SSL web-mode VPN?

Hi, we want to let the remote SSL VPN users to use captive portal when they try to connect to web-mode ssl vpn.

when the user access https://x.x.x.x:10443 from the internet, he will will the captive portal instead of SSL VPN portal page, after captive portal login successful, then redirect to internet web server. Is it possible to make it works? Please advise, thanks in advance.