Well, as you said, there's an ActiveX component to embed .swf files. You just have to define an ActiveXControl in your .dcf file whith programId=Shockwaveflash.Shockwaveflash.9 (or any other version), inPlaceActivate=yes if you want to have it embeded onto the surface of your document.
You need to have a script to control your Flash movie (at least initialization). You can define 3 functions to do it : controlName_OnInitialize, controlName_OnClose and controlName_OnCancel (see customizer's guide for further informations). Typically, you will have in your controlName_OnInitialize function something like :
controlName.Movie = "your_file.swf";
controlName.Loop = false;
It's possible to establish communication beetween Arbortext and your Flash movie, if you need to do it, I should be able to give you some tips about it.