You need to model the hierarchical relationship between account and group account ...
You want to show if the the Account no is 900654 then 'Space Rental' use case statement.
edit formula write like below:
Ex Case when accountnumber=900654 then 'Space Rental'
casw when accountnumber=900760 then 'Administrative Overhead' else accountnumber end
That's the one-time solution ... USE of information drives design. Spend the effort and do it right; then it will perform better and is much more usable.
yes Thomos, I gree this is one time solution. I given to solve current requirement.