Evaluating text as an expression

[Duncan Miller]

I am trying to set up a table where the returned value is a result of 
evaluating an expression that is stored as text (or varchar).

The idea is to have a table with a couple of fields that can contain 
numeric values or expressions eg

Name    Fred
Years   3
Commission base         10%
Commission      Commission Base + (Years * 2)%


I sort imagines that I could do it like SELECT Name, 
Evaluate(Commission) or as a subquery.

Another example I have is to be able to store queries in a table and be 
able to call them in one call to the database rather than through the 
provider eg

Select evaluate(queryText) from queryTable where queryId = x

This is probably a bit more redundant now that 5 has stored procedures 
etc but still...

any ideas

Thanks
Duncan