車輪の再発明してる感が半端ないが応用が効きそうなのでメモ。
function getParentDir(byval path)
dim splitedPath
splitedPath = split(path, "\")
splitedPath(ubound(splitedPath)) = ""
getParentDir = join(splitedPath, "\")
end function
msgbox getParentDir("C:\hoge\fuga\poge.txt")
' C:\hoge\fuga\
msgbox getParentDir("\\hoge\fuga\poge.txt")
' \\hoge\fuga\
msgbox getParentDir("\\192.168.0.100\hoge\fuga\poge.txt")
' \\192.168.0.100\hoge\fuga\