Controls Within a DDL

I've been given the task of designing a UI in which the users will select the shipping dates of their recurring orders.  There are several ways to specify this so I'm trying to accommodate several of the different approaches.  One thing that's a constant is that there is very little available screen real estate to work with.
It occurred to me that one solution would be into introduce a "complex" dropdown listbox (DDL) that allowed controls to be placed within each item of the DDL.  Here's a quick example I found of a more elaborate DDL: http://assets.devx.com/articlefigs/43335Fig4_CatchyComboBox.JPG In my case, there would be 3 items in the DDL, which would contain the following: 0 > Frequency: [DDL] 1 > [DDL] Weeks  [DDL] Months 2 > ["Select Dates" button] ----> Calendar Control In essence, what I'd be do ...