sending results of function query to range query

[Kevin Osborn]

I am not sure if I can use function queries this way. I have a query like 
this"attributeX:[* TO ?]" in my DB. I replace the ? with input from the front 
end. Obviously, this works fine. However, what I really want to do is 
"attributeX:[* TO (3 * ?)]" Is there anyway to embed the results of a function 
query inside the query?