locking part of look up formula

[Gil]

I am using a simple table from another sheet to look up a value that is part
of a formula. The formula is as follows:
=VLOOKUP(Sheet1!AV3,Sheet3!A1:B4,2,FALSE)*T3
I have 500 data lines in which to input the formula so I want to copy it
rather than type it 500 times. When I copy the formula, the copied formula
looks like this:
=VLOOKUP(Sheet1!AV4,Sheet3!A2:B5,2,FALSE)*T4 and I want it to look like this:
=VLOOKUP(Sheet1!AV4,Sheet3!A1:B4,2,FALSE)*T4. The difference is that when
copied the formula changes all of the values and I do not want to change the
A1:B4 value.

Is there a way to "lock" that portion of the formula?

 

[Jim Thomlinson]

$A$1:$A$B4

 

[Gil]

Thank you Jim. You saved me and my research assistant a lot of work.
Hooray!!!!!