It looks like this can be done. I found the following in the
"Integration API Developer's Guide" for sitebuilder:
If dealing with Sitebuilder for Unix, use the URLs in the following formats:
To log in to the control panel as administrator:
http://<sb-example-host.com>/external_login.php?Login=admin&Password=admin
To log in to the wizard as site owner:
http://<sb-example-host.com>/external_login.php?Login=siteowner&Password=siteowner
To log in to the control panel as site owner:
http://<sb-example-host.com>/external_login.php?Login=siteowner&Password=siteowner&ShowAdmin=true
To login to the control panel with a specific language and skin:
http://<sb-example-host.com>/external_login.php?Login=admin&Password=admin&Skin=AquaCompact&&Language=de-DE
To log in as site owner directly to the page of editing a particular site (specified by its ID):
http://<sb-example-host.com>/external_login.php?Login=siteowner&Password=siteowner&SiteID=b2e11f743e10475dcaa60f81b271caaa
If dealing with Sitebuilder for Windows, use the URLs in the following formats:
To log in to the control panel as administrator:
http://<sb-example-host.com>/ExternalLogin.ashx?Login=admin&Password=admin
To log in to the wizard as site owner:
http://<sb-example-host.com>/ExternalLogin.ashx?Login=siteowner&Password=siteowner
To log in to the control panel as site owner:
http://<sb-example-host.com>/ExternalLogin.ashx?Login=siteowner&Password=siteowner&ShowAdmin=true
To login to the control panel with a specific language and skin:
http://<sb-example-host.com>/ExternalLogin.ashx?Login=admin&Password=admin&Skin=AquaCompact&&Language=de-DE
To log in as site owner directly to the page of editing a particular site (specified by its ID):
http://<sb-example-host.com>/ExternalLogin.ashx?Login=siteowner&Password=siteowner&SiteID=b2e11f743e10475dcaa60f81b271caaa