Formula help for including text if cell is not blank

I have a large spreadsheet that I am linking data from to a smaller spreadsheet. I need a formula for the following: If cell is not blank, copy text from cell

Thanks

Something like this:

=IF(Sheet1!A1="","",Sheet1!A1)

You may need to include the full path and filename if you are referring to different workbooks rather than different worksheets in the same workbook - the syntax would be something like:

'full_path[filename.xlsx]sheetname'!

instead of the Sheet1 that I have used above.

Hope this helps.

Pete