I'm not sure I understand your scenario. Do you need a "Help" section for a dialog? If this is the case, this is a possible implementation:
1. Go to "Dialogs" page and select the dialog containing the IP Address and the Port Number.
2. Create a new "Hyperlink" control on this dialog by clicking on "Control" toolbar button. You could change this button's label by editing the "Text" field in "Properties" view.
3. Select this Hyperlink and go to its "Publish Events" view. Here click on "New..." button and select "Display a specific Dialog" option
4. Now the dialog containing the IP Address and the Port Number will have a child dialog named "NewDialog". Select this dialog from Dialogs page and enter the help or description information you want, by adding, for example, a new "Static Text" control from "Control" toolbar button.
Let me explain you clearly about the requirement, example when we open the tool if we press F1 key in key board it explains about the selection option description like Product Details.
In such way i need to find the html page or pdf document describing about the selected dialog and its controls description.
Unfortunately Windows Installer doesn't support hot keys feature. However, you could implement your scenario using a push button that would trigger a custom action that opens the help file. Please take a look on my colleague's reply on this topic with a similar subject : Keyboard shortcuts handling