Visual Basic

Dim oNet As Object
Dim arrDrives() As String

Try
    oNet = CreateObject("Wscript.Network")

    '
    ' GetLogicalDrives returns an array with each entry
    ' being of the form "X:\" where X is the drive letter.
    '
    arrDrives = System.Environment.GetLogicalDrives

    '
    ' Detect if it is already mapped.
    '
    If arrDrives.IndexOf(arrDrives, sDriveLetter.ToUpper & "\") >= arrDrives.GetLowerBound(0) Then
        '
        ' optionally remove the drive
        '
        'oNet.RemoveNetworkDrive(sDriveLetter)
    End If

    '
    ' Map it.
    '
    Dim s As String = ""

    s = oNet.MapNetworkDrive(sDriveLetter, sUNCPath)

    '
    ' Report any errors by throwing an exception.
    '
    If s <> "" Then
        Dim ex As New IOException("Unable to map the " & sDriveLetter & " drive.  " & s & " - " & Err.Description)
        Throw ex
    End If

Catch ex As Exception

End Try

if filecontent.indexof(texttolook)<>-1 then yourcounter += 1

Construct a Regex for your search string
Initialize your count variable to 0
For each file in the directory
  Open the file
  Read it to the end and store the string
  Find the number of matches to the regex in the string
  Increment your count variable by that number

Dim i As Integer
Dim r As Regex 
r = New Regex("me@here.com.au")
Dim fileEntries As String() = Directory.GetFiles(targetDirectory)
Dim fileName As String
For Each fileName In fileEntries
  i = i + r.Matches(File.OpenText(fileName).ReadToEnd()).Count
Next