Max row number is currently 1048576, so you could give the range with a mixed relative/absolute address:
Older software or different titles may have a different “max rows” value. Also, some scenarios do not work well with this kind of addressing (row insertion/deletion is one possible pitfall).
Use A:A for entire column A. Use OFFSET() to move starting point, but then you also need to reduce number of rows to avoid error.
To have a dynamic offset value, you can use the ROW() function with a relative cell address instead. This way you can copy formula up/down and have the starting point follow, while retaining the “bottom” end point. ROW() without a parameter returns the row number for current cell (where the formula is).
INDIRECT() may be another way to reach your goal.
Please add a comment if this does not address your issue.
More detail about your layout can be added as a comment to your question (or perhaps an attached file - edit your question and use the paperclip icon), and may yield a better solution.