Well, these rows and columns are default and system based that come as a packaged deal with Excel.
May I suggest one or both of the following.
Highlight/Select the range of columns and rows that you need (19/3000). Right-click to select Format Cell, in the dialog box, select the Protection tab, and then deselect the "Locked" option. Next, click on Review from the Ribbon Tab and select the Protect Sheet from the Protect Group. Ensure only the "Select unlocked cells" checkbox is checked. You may set a password. Click ok.
This will ensure only the 19 columns and 3000 rows are selectable while all the remaining ones will be locked.
Alternatively, you could select the column after 19th, while holding down the Control + Shift keys, use the right arrow to select all columns to the right of the col20, which end at colXFD. Then right-click and select Hide. Do the same for the rows. Move to the row below the 3000th, ctr + shift + down arrow to select everything below. Right-click and choose Hide. You are now left with only the range of cells you wanted.
Of course, there are several other solutions that might be better than either of the above. Best of luck.
