VB Function InStr() Equivalent in C++

I'm converting VB to C++. I don't know how to convert InStr() to C++. I have manged Left() but InStr() is not available in C++. Can Someone please tell me how to convert InStr() to C++.

Public Function CW_Name(ByVal alIndex As Long) As String
     If Not Fb_ValidIndex(alIndex) Then Exit Function
     '-->DT - 08/10/11 - SIT#47953 - Truncate string on Chr(0)
     Dim liMark As Integer
     liMark = InStr(1, CurrentMat.Description, Chr(0))
     If liMark Then
          CW_Name = Left(CurrentMat.Description, liMark - 1)
     Else
          CW_Name = CurrentMat.Description
     End If
     '<--DT - 08/10/11 - SIT#47953 - Truncate string on Chr(0)
End Function

Thanks in Advance.