How to arrange strings like that?

Hello :)
It's my 2nd day im working on a function to arrange any string in a certain pattern, and after all my efforts im forwarding this query here.

I want to arrange any string like -
Suppose the string is "google" Now i want to arrange them in a listbox as -

g-oogle
go-ogle
goo-gle
goog-le
googl-e
g-o-o-g-l-e
g-o-gle

and so on [all possible patterns (without any duplicate entry)]..

Note: "-" can be many times but shouldn't be duel like "go--ogle"

I hope you can help me on this :)

Thanks
Regards,