If you are using a custom number format 000+00, and the numbers are entered
as numbers, the calculation will work and display correctly.

If, however, you type the number in as 100+00, instead of as 10000, it will
be interpreted as text, and hence your #VALUE! error.

If some or all of your "numbers" are text, you could use something like
=LEFT(A1,3)+LEFT(A2,3)&"+"&RIGHT(A1,2)+RIGHT(A2,2) , which of course gives
the answer as text.
=(LEFT(A1,3)+LEFT(A2,3))*100+RIGHT(A1,2)+RIGHT(A2, 2) would give a number
which could be formatted 000+00.
--
David Biddulph

"Jupraven" wrote in message
...
I'm trying to calculate the distance between two known Stations (i.e.
100+00
and 200+00) for an easy measure of plan quantities. The Difference
between
these two points is 100+00, and the sum is 300+00; obviously (or 100 and
300
respectfully). Ok, so how is this done in Excel to arrive with an answer
in
either working number format?
The formatting is a custom type: 000+00, but the cell still references
#VALUE.