Currently, my site generates a unique Customer ID for each user. The variable name for this in my database is CustomerID. How do I get the SID function of an Affiliate link to query this value from my database. So when a customer with a CustomerID of 55 makes a click or transaction through the affiliate link. The link queries my database and returns the correct CustomerID and inputs it into the SID value. This way when I run my reports I can see exactly when, where, and how much Customer 55 spent, so that I can reward him based on his transaction?

What exactly do I put in the SID field of the link builder tool to get the affiliate link to query my database and return the specific SID# so I can identify my user when he or she completes the purchase?