How to Programmatically Select a Feature for the User

Hi,

In my SetupBuilder program I several features that can be installed. All are visable, not required, or installed by default.
I'm trying to conditionally select a feature to be installed if one of the other features is installed.
i.e.
If Feature A is selected, and Feature B is not already selected, then select Feature B for the user.

Is there a way to do this? I see that I'm not supposed to modify %_SB_FEATURESID%. So far all that I have seen are old posts stating that this functionality will be available in version 7.2+. I am currently using 7.3.3228

Here's a sample of my code:

If %_SB_DIALOGID% Equals "3" Then
If Feature "A" selected Then
If Feature "B" not selected Then
???Programmatically make Feature "B" selected???
End
End
End

Thanks for any help you can provide!

Nick