Yes, VLOOKUP can search an entire worksheet instead of a range of cells. To do this, you can use the following steps:

1. Click on the cell where you want to enter the VLOOKUP formula.
2. Type the formula "=VLOOKUP(" without the quotes.
3. Click on the cell that contains the value you want to look up.
4. Type a comma "," without the quotes.
5. Click on the worksheet tab that contains the data you want to search.
6. Click on any cell in the worksheet to select it.
7. Type a colon ":" without the quotes.
8. Press the "Ctrl" key on your keyboard and click on the last cell in the worksheet that you want to search.
9. Type a comma "," without the quotes.
10. Enter the column number that contains the data you want to return.
11. Type a closing parenthesis ")" without the quotes.
12. Press "Enter" on your keyboard to complete the formula.

For example, if you want to search the entire worksheet named "Data" for the value in cell A1 and return the value in column B, the formula would be:

Note that the "FALSE" at the end of the formula is used to indicate an exact match. If you want to allow for approximate matches, you can use "TRUE" instead.

Also, when you copy the formula to other cells, the cell range will automatically adjust based on the relative position of the cells. However, the worksheet reference (e.g. "Data!A:B") will remain the same.