Use the Formula Name dialog box to specify a name for your formula or custom function.
When placed on the report, the formula will appear as @YourFormulaName if you have "Show Field Names" selected in the Default Settings dialog box.
Use Expert
Click the Use Expert button if you want to use the Formula Expert for creating your formula.
Use Editor
Click the Use Editor button if you want to use the Formula Editor dialog box for creating your formula.
Formula Expert | Formula Workshop | Formula Editor Dialog Box | Default Settings Dialog Box | Field Explorer | Custom Function Name Dialog Box