Yes, UserForms in Excel are nice to use if you have a defined structure of items that you want to store. First of all, what version of Excel are you using? I will assume you are using 2000 or 2002. If not, the following may not work quite the same way in earlier versions.
What you would do is design the UserForm how you would like it to look? You can get as fancy as you want. To create a UserForm, you'll need to go into the Visual Basic Editor by pressing Alt-F11 or Tools-> Macro-> Visual Basic Editor. In the VBA Project Explorer on the left, you'd right-click on the project name (e.g. VBAProject(MyProject)) and goto Insert-> UserForm. You can design the UserForm from there by inserting text boxes, your drop-down combo boxes, and a "Submit" command button. You can then add VBA code to do the work for you.
If all this sounds Greek, then you probably would be getting into something too difficult than needed (unless, of course, you like learning new stuff), or you might want to hire a VBA programmer. If you're still interested in this method and want to continue and need further assistance, let me know and I'll help you along to the finish.
Hope this helps!