I have a macro that creates Sheet9 as needed. On Sheet1 I need to SUM values
from Sheet9 when it exists.

Currently I use a basic formula but when the sheet gets automatically deleted
and recreated, using a macro, the formula errors and does not "fix" itself when
Sheet9 gets recreated.

I prefer to use a macro where I can specify a Sheet/Cell to place the SUM, when
Sheet9 exists... but if you have a formula that will stop if from erroring that
would work too.

thx for the help!