How do I print a .dat file?

[Ninja12]

I created a program, and the input data gathered from the program is stored in a .dat file. There are three files. I want print the third file. My files are named (1), (2) (3). I use the Common Dialog Box to print the file. But the coding I am using doesn't work. An error message appears saying "Bad file name or number"
Is there any mistake in my coding?
Can I get some help please?
Thanks

This is the coding for the printing I am using

Private Sub cmdPrint_Click()
cmndlgPrint.ShowPrinter
 
Printer.Print Tab(10); "Room Num"; Tab(10); "Computer Rental"; Tab(10); "TV rental"; Tab(10); "Fixed Rental"; Tab(10); "Water Rental"; Tab(10); "Electricity Rental"; Tab(10); "Overall rent"
 
Do While Not EOF(3)
Printer.Print Tab(15); strMonth1; Tab(20); strRoomNum1; Tab(20); curFixedRentTV1; Tab(20); curFixedRentComp1; Tab(20); curFixedRent; Tab(20); curRentWater; Tab(20); curElecFinal; Tab(20); curFinal
Loop
 
Printer.Print
 
End Sub
 

[Killer42]

...
Do While Not EOF(3)

Is this the statement which produces the error?

If so, you need to ensure the file is open for reading befoer executing this code.