Formula with static and dynamic cell references

I'm using the VLOOKUP function to find a specific value in a table and enter its corresponding value into a cell. The formula is below:

=VLOOKUP(Q2,HBF!A1:B72,2,FALSE)

This formula works fine for the first cell, but when I copy it into cells below it in my table, the cell references change. What I want the function to do is change the lookup_value (Q2) but leave the table array (HBF!A1:B72) the same. So I want the formula to look something like this:

=VLOOKUP(Q3,HBF!A1:B72,2,FALSE)
=VLOOKUP(Q4,HBF!A1:B72,2,FALSE)
=VLOOKUP(Q5,HBF!A1:B72,2,FALSE)
=VLOOKUP(Q6,HBF!A1:B72,2,FALSE)

Instead, I'm getting something like this:

=VLOOKUP(Q3,HBF!A2:B73,2,FALSE)
=VLOOKUP(Q4,HBF!A3:B74,2,FALSE)
=VLOOKUP(Q5,HBF!A4:B75,2,FALSE)
=VLOOKUP(Q6,HBF!A5:B76,2,FALSE)

Can anyone suggest how I might change the "lookup_value" depending on the cell, but keep the "table_array" field the same?

Thanks

-zack