There is a product which allows exactly that sort of thing and also has integration with LANDesk. I'd describe it as a professional survey tool. It has a survey tool design front end, can stop survyes from going to people who have had too many, allows opting out, gathers a given number of results and then stops, allows multiple surveys to run against different criteria, has a full blown survey design tool with skip logic rules, integrated reports and so on.
Enough from me - Capisce survey tool is the chap concerned, google will find it
Alternatively, DBDescription.pdf or PrebuiltContent.pdf (depending on your LDSD version) explains how to change the frequency of the surveys in the section about the Incident with Survey process.