Command Line Options

I have a problem. On my spalsh screen I test if there is a determined file using this code:

    ' Check command options
    If Command <> "" Then
        If Chr(34) <> Left(Command, 1) Then
            FileName = Command
        Else
            lencommand% = Len(Command) - 2
            FileName$ = Mid(Command, 2, lencommand%)
        End If
    Else
    End If
   
    ' check file
    On Error GoTo nofile:
    Dim strTemp As String * 1
    Dim i As Integer
    i = 0
    Open "file.txt" For Input As 1#
    Do Until EOF(1)
    i% = i% + 1
    Line Input #1, strTemp
    Loop
    Close #1
    If i% <> 70 Or FileLen("file.txt") <> 6368 Then
nofile:
    MsgBox "No file"
    End
    Else
    End If

This works fine if there is no command line. When I drag a file to the aplication icon it causes an error opening the file that I want to check. Is there anything I can do? I don't understand why. It's supposed to open and check file.txt wherever the aplication is. (this file will be there as well)

Thank you