I know how to import a registry key, but do not know how to get text entered in form and redirect the output to the windows registry.
I need the text of the custom form is also recorded in the registry, rather than just being recorded in Landesk DB.
I wouldn't use Custom Data forms than, but rather use some kind of script (VBscript for example) that asks the question and you can redirect the output wherever you want. You can pick this up by inventorying the registry key also, if you want.
Look here for an idea on a VBscript: