Selecting data in another spreadsheet

[Spellchamp]

Hi,
I'm trying to select a range of cells in a worksheet that's open on the computer but is not the workbook where the macro is running.
I keep getting this message though:
"Subscript out of range"
with the following line highlighted:
Workbooks("Book1").Activate

I understand it has something to do with not being able to open Book1(where the data I want to select is stored) but I have no idea why.
Any help would be appreciated
Thanks

 

[Jett Midknight]

You should be using Windows("Book1.xlsx").Activate, or Windows("Book1.xls").Activate depending on what the file extension of Book1 is

 

[Spellchamp]

Boy do I feel silly now. Thanks so much it worked perfectly!

 

[Spellchamp]

So that worked, but what I'm trying to do is select a range of values in the other worksheet based on an input from the user. I was trying to use:

Set x = Range(Cells(1, 1), Cells(3, 3))
ActiveSheet.x.Select

but I get the error "Object doesn't support this property or method"
Is there a way I can select a range of cells based on a numeric value using this method?