You could use a mask column (or use a mask in a command to exclude them).
If you want to remove entirely (which it sounds like maybe you do), you can select the columns using the Find bar, select the rows, and then use Replace selected rows with empty.
Here are the steps …
1- Click Command-F
2 – Set the filter, Value < 0
3 – Click any row, and then use Command-A to select all
4 – Click Done in the Find bar. This will show all the rows again.
5 – Right click on the column header and select Empty selected rows
You’re done! If you use this approach, you can only do one column at a time. Hide all other columns from view.
Hope that helps!