Expression to extract Fixed Value from Random value

[Josh Verran]

Not sure the best way to describe this but I'll give it a go.

On a project we might have 5 different walls, the difference might be composite, might be properties, might be complex profile, might be combination.

Have a schedule which shows these great.

Want to Graphic override each of these five to a different colour, eg the 100mm conc wall to red, the 150mm timber wall to blue.

Can do this fine, but the criteria of each graphic override rule is specific to that wall type, eg element is wall, composite is x, property is y.

On the next project there might be 5 totally different wall types, but still want to Graphic override the first type to red, the second to blue and so on.

There could be in excess of 30 wall types that could be used across all projects, but less than say 5 on each individual project if that makes sense.

So graphic overriding for each type would be too onerous and would need over 30 colours while only 5 colours are required to show the differences.

So what I'm hoping for is some kind of expression, that regardless of the wall types (within a set criteria), will return a 1,2,3,4 or 5, based on whatever it can.

Perhaps an expression that multiples the lengths of a type by say 5,000 then uses a ROUNDUP function then a LEFT function to return the first digit???

Any ideas guys?

Really hope the above makes some kind of sense.