What do you mean by "dynamic range"?
Has the range of cells been given a name (eg. "Sales") in the workbook that is closed (better), or is it just a range of cells (eg. A1:D34)?
Either way, you can just type the formula into the open spreadsheet, viz;
Range has been named:
=+'C:MyWorkbook.xls'!Sales
or
Range has NOT been named:
=+'C:[MyWorkbook.xls]Sheet1'!$A$1
HTH
BigC