pass file handler to functions in DLL

Dear all,

I have written a DLL (ActiveX) to hidden the process from the main program. And I already created a new instance
Dim NTA as new NTA_Lib

However, when I click the button in the form, error happened: "Bad filename or number". Please help. Thanks all.

Codes as below:
<in Main program>
Public Sub BT1_click()
DIM FH1 as integer
FH1 = 1

Open txtInputPath For Input As #FH1
NTA.HProcess(FH1)
End Sub

<in DLL>
Public Sub HProcess(IHandler as Integer)
Do Until (EOF(IHandler))
' code here
Loop
End Sub

Instead of FH1 = 1 do this:

FH1 = FreeFile

If you happen to create multiple instances of the dll, make sure you keep the filenumbers in sync. A better idea might be to pass the drive:\path\filename.ext string to the dll, and then process the file. That way the filenumber is private to the dll instance.