Visual C++ :: How To Set Starting Root Directory That Selects A Folder Name

The following code is useful to allow a user to select a particular folder in the disk directory.

Code:
void OpenFolder() {
LPMALLOC pMalloc; //,pMalloc2;
CString strDirectory;
BROWSEINFO bi;
// Gets the Shell's default allocator
wchar_t pszBuffer[MAX_PATH];

[Code] ....

However, if one uses this code over and over, one quickly becomes tired of threading one's way all the way from root directory C:. There is undoubtedly some way to designate a starting directory. The most obvious candidate to set such a target is the:

Code:
bi.pidlRoot = NULL;

But attempting to set bi.pidlRoot to a CString (directory address) errors because 'no suiitable conversion from CString to LPCITEMIDLIST exists'

How can I set the code to open at a designated address in the directory tree?