You can do a basic audit report using a query, it's not brilliant but then I dont think SMS is the right tool for a software audit. I've used a few and SMS is the least flexible or helpful.
If you create a new query, click Edit Query Statement, then Show Query Language, then paste the following text into it.
select SMS_R_System.Name, SMS_G_System_SoftwareProduct.ProductName, SMS_G_System_SoftwareProduct.ProductVersion from SMS_R_System inner join SMS_G_System_SoftwareProduct on SMS_G_System_SoftwareProduct.ResourceID = SMS_R_System.ResourceId order by SMS_R_System.Name DESC
Its a simple report, showing PC Name, Product and Version. I'm sure you'll be able to modify it to suit your needs.
Take care.