Adding a build expression on query condition
Use this feature when you need to add a condition (including a user-defined string or a mathematical expression) that is based not on the entire content of the attribute as is, but on part of the attribute, a function of the attribute, or a function that combines more than one attribute.
Once the query conditions are saved, there is an Add Expression icon 
icon, next to the query conditions, that opens the Build Expression pane. Use it to add
user-defined strings and mathematical expressions.
When there is a build expression defined, there is a red asterisk next to the Build Expression
icon 
.
An example:
Return the location of the string 150.1, from the value 192.150.1.x., where the
string 150.1 is at the fifth character of the value. The string
150.1 represents all instances of Client IP matching the 5 characters listed.
When the function is run in the Expression field, it returns a value, and that value should be in the entry box.
Use the function, INSTR(:attribute, '150.1') with a "5" value in the entry box
next to the Add Expression icon to return the records with
150.1 in the fifth location.
If the function is INSTR(:attribute, '150.1') = 5, then it becomes a Boolean
phrase, and the only values in the entry box are 0 or 1.
Type the INSTR(:attribute, '150.1') expression in the separate Build Expression
window.
Test the validity of the expression in the Build Expression window.
Another example: LENGTH(:attribute) >= 40, which returns the length of any SQL
statement greater than 40 characters. The expression might or might not contain references to the
actual attribute and can also contain references to other attributes.