How to deal with VB ByRef in Delphi

I am in the process of converting a VB program to Delphi. There are many calls to an external DLL that need to be made. One of these functions is:

Declare Function rtdGetParams Lib "rtdsdk.dll" (ByVal nBoardNum As Integer, ByVal nParamNum As Integer, ByRef lpParamVal As Long) As Integer

And its' use in the VB program is:

    If (rtdGetParams(0, CURRENT_POSITION, lpCurrPos) = VP_BS_ERROR) Then
        IDC_TIMER.Enabled = False
        MsgBox "rtdGetParams(CURRENT_POSITION) Failure", vbIconStop, "Error Report"
        nBoardState = VP_BS_ERROR
        IDC_TIMER.Enabled = False
    Else
        IDC_SCROLLBAR_CURRENT_FRAME.Value = lpCurrPos
    End If

The question is: How do I convert the first line to work with Delphi?

Tom