Do you know what Cartesian equations are? They're equations mainly to do
with circles, and this is what you need as far as i can tell.

Say a reference on the map is 100 miles East and 500 miles North and
you want to know if something is within 1000 miles of the central
point.
Assuming the certain something you are searching for is 70 East and 400
North, you need to know if this reference is within the 1000 mile radius
of the point(100,500) Let X be 100 and Y be 500 (as it is)

=IF(POWER((100-70),2)+POWER((500-400),2)1000,"Outside 1000 mile
radius",IF(POWER((100-70),2)+POWER((500-400),2)=1000,"On the 1000 mile
radius","Within the 1000 mile radius"))

This equation will tell you if any point is within/outside any other
reference point.

Sorry if this is not what you mean, but certainly sounds like it.
A general equation is this:

=IF(POWER((A1-A2),2)+POWER((A3-A4),2)A5,"Outside
circumference",IF(POWER((A1-A2),2)+POWER((A3-A4),2)=A5,"On
circumference","Within circumference"))

A1 is the distance East of the central point from the origin
A2 is the distance East of another point from the origin
A3 is the distance North of the central point from the origin
A4 is the distance North of another point from the origin
A5 is the radius that is to be measured from the the central point

With this, you shouldn't need a macro.


--
Faz
------------------------------------------------------------------------
Faz's Profile: http://www.excelforum.com/member.php...o&userid=27830
View this thread: http://www.excelforum.com/showthread...hreadid=474044