From Text to Math: VBA or Excel 4 Macro Function: EVALUATION
See Mr Excel and excelisfun use two methods to convert a text string to a match expression that can calculate the correct answer:
1. VBA code
2. SUBSTITUTE, SUBSTITUTE formulas and the Excel 4 Macro Function used in a Defined Name. See the keyboard to insert a Macro Sheet which allows you to test Excel 4 Macro Functions before putting them into Defined Name Formula.