I need to create a drop down list like this one. I don't know how?
Who can help me with this?
What exactly ist your problem in creating that component? You obviously already have created it or where does the screenshot stems from?
What I see looks like a Webcontrol which can be inserted via "Menu:Insert-Control-Web Control...-List box/Combo box" and then the four names (HEB100, etc.) have to be manually typed in along with their appropriate return values (HEB100 --> 3, etc.). At last set display height from the default 4 to 1 and you have the component exactly as shown.
The benefit of webcontrols is, that they are easier to handle, look better and when the sheet is opened you will not be asked for security reasons if you want to disable scripting.
The drawback of webcontrols is that you have to type in all the information manually (which is no big problem with a selection just out of four) and are much less flexible. Using scripted components you could extract the information to be displayed by your dropdown from the matrix P itself (it would have to be defined before the component of course - I try to avoid global assignments) and changing a name or adding a row in P would immedeatly affact the drop down accordingly.
If you are interested - you can find a fine collection of scripted components for various purposed here: