The point parent was trying to make is that the column might have to be configured as supporting text, which would happen if you point it to V#Annotation (regardless of what the formula does).
To be honest, the best way to approach these problems is typically to build a little U8 DynamicCalc formula that will do the calculations and return "OK"/"Check" (ideally for a text-supporting view like Annotation).
Rough outline of such a U8 off the top of my head:
if api.View.isAnnotationType then
' example check
if api.Data.GetDataCell("A#Something - A#SomethingElse") = 0 then
return "OK"
else
return "Check Details"
end if
end if
You'd then point the column at U8#MyNewMember:V#Annotation to display the generated values.
Depending on the use case, it might also be enough to simply highlight "check details" rows with Conditional Formatting and be done with it:
If CellAmount > 0 then
BackgroundColor = Red
TextColor = White
End if