Copy/pasting a custom option in Folder options

[SlickRCBD]

I'm having a brain fart here configuring some file types. I'm trying
to make an option to "Open with Office" on several different file
types, so they will keep their defaults but let me open them directly
to Office when necessary.

I seem to remember that there was a faster way to do this than typing
it in for each file with all the clicks and fields. A way to copy what
I want and paste it in for each file type. I think it involved
RegEdit.
I can't store the "OpenWithOffice" option on the clipboard in the
Folder Options->File Types dialog box, as right clicking on it only
gives me the "what's this?" option. Which incidentally says that the
feature I'm using is designed for this purpose.

I might just be confusing this with a newer version of WIndows like
XP. I could have sworn I did something like this though with Open
Office on my desktop a few years back. Does it ring a bell with anyone?