I have an excel file that contains that Main(). I have WriteLog(fnum,
message) function in a different excel addin file .xla. When I use
WriteLog to write to a already opened file I get "Bad file or number".
Apparently, the file number is not available in that module before
entering into the module in the addin.

Sub Main()
REPORT_FILE_NUMBER = FreeFile
Open ThisWorkbook.Sheets(1).Range("outputfile").value For Output
Access Write As #REPORT_FILE_NUMBER
Print #REPORT_FILE_NUMBER, "My message" '<== This works fine

WriteLog( REPORT_FILE_NUMBER, "My message" )

Print #REPORT_FILE_NUMBER, "My message" '<== This works fine also!!
Close #REPORT_FILE_NUMBER
End Sub

'This sub is in an excel addin. It works fine if not an excel addin but
a different module in the same file.
Sub WriteLog( Optional dest, msg As String )
Print #dest, msg '<=== I get error number 52, bad file name or
number here
End Sub

Please help. Thanks