How to open windows explorer to a specific start point?

We have a directory for which we drop in files to be emailed out by our sales team. This code takes me to the "To_Email" directory but I'd like to go a step further and go to the start of, for example, clients that begin with the letter "R". (see image). I realize I can just click in there and hit r but I'd rather do it in code. Ultimately the idea is to find the email file I just created and copy the file path. That way I can include the path on the proof sheet so the sales team would know exactly where to find it.

Sub NavigateToEmail()
Dim sPath As String
sPath = "\\G-SERVER\To_E-mail"
retVal = Shell("explorer.exe " & sPath, vbNormalFocus)
End Sub