Regualr Expression for: Folder path back one slash

[stupomer]

Hi,
I have been trying to figure out the RegEx for taking a folder path back one level

e.g.

folderpath = "C:\Test Level Top\Test Level Top minus 1\Test Level Top Minus 2

to become

upfolderpath = "C:\Test Level Top\Test Level Top minus 1"

I know it's something with substrings and replacerx (e.g. "[sample pattern $2, $1),
but I get confused when it's the LAST of something that I have to remove (i.e. how do you know its the last....)

Any good resources on getting better at RegEx that people know. Maybe a place with exercises or something.

Stuart