Hit F1 for HELP and search on "One-Click Access to Survey".
Extract from the Sawtooth Software HELP ...
If you want respondents to click a link that automatically logs them into a survey and supplies their passwords and/or additional "passed-in" data (that you've defined in the passwords table), you should create a URL that links respondents directly to the Perl script located in the cgi-bin directory. When respondents click such a link to start the survey, they skip the Start page (page 1). The following text included in an email message starts a survey with a studyname "tep1" located in the "gonzo" study root directory, with password fields named myusername and mypassword, with valid values of "michael" and "A6Z99":
http://www.sawtoothsoftware.com/gonzo/cgi-bin/ciwweb.pl?studyname=tep1&myusername=michael&mypassword=A6Z99
You can also pass additional variables into the data set, as long as those are defined as Pass-in Fields within the Questionnaire Access and Passwords dialog. For example, if we define a Pass-in Field called panelid, we can specify this directly following any password information, as below:
http://www.sawtoothsoftware.com/gonzo/cgi-bin/ciwweb.pl?studyname=tep1&myusername=michael&mypassword=A6Z99&panelid=7362836
When respondents start the survey by clicking the hyperlink, if the passwords are valid (and the quota is not complete), the respondent is sent to the page following the password screen. If the respondent is restarting an interview, the page where he/she left off is displayed. Any passed in information is stored in the database, as if it were any other question in the survey.
When you upload you survey to the server, you will also see the one-click survey link. Use this and insert any of you allowable passwords into the link.