In order to obtain new Actions object call WebDriver.Actions.
var actions = WebDriver.Actions();
Then construct your action, build and perform it.
var el1 = WebDriver.FindElementByXPath("//select[@id='ctrl07']/option[1]");
var el2 = WebDriver.FindElementByXPath("//select[@id='ctrl07']/option[2]");
var el3 = WebDriver.FindElementByXPath("//select[@id='ctrl07']/option[3]");
actions.KeyDown("Shift").Click(el1).Click(el2).Click(el3).KeyUp("Shift").Perform();
Here is one liner example.
WebDriver.Actions().KeyDown("Shift").Click(el1).Click(el2).Click(el3).KeyUp("Shift").Perform();
Actions class is described in Rapise help.
Note: If in your code you have a reference to Rapise object then you may address corresponding element via `.element`:
var obj = SeS('username');
WebDriver.Actions.Click(obj.element);
Check out the sample test on GitHub.