How to Create a User Defined Function in Microsoft Excel 1. Steps. Learning to program in VBA or in any other language can take some time and a detailed tutorial. However, functions usually have small code blocks and use very few features of a language. The more useful elements of the VBA language are. The If block, which allows you to execute a part of the code only if a condition is met. For example Public Function Course Resultgrade As Integer As String. If grade 5 Then. Course. Result ApprovedElse. Course. Result RejectedEnd If. End Function. Notice the elements in an If code block IF condition THEN code ELSE code END IF. The Else keyword along with the second part of the code are optional. The Do block, which executes a part of the code While or Until a condition is met. For example Public Function Is. Primevalue As Integer As Boolean. Help using excel functions, graphs and spreadsheet testing. Dim i As Integeri 2. Is. Prime True. Do. If value i Intvalue i Then. Is. Prime False. End Ifi i 1. Loop While i lt value And Is. Prime True. End Function. Notice the elements again DO code LOOP WHILEUNTIL condition. Notice also the second line in which a variable is declared. You can add variables to your code so you can use them later. Variables act as temporary values inside the code. Excel Function Help File' title='Excel Function Help File' />Finally, notice the declaration of the function as BOOLEAN, which is a datatype that allows only the TRUE and FALSE values. This method of determining if a number is prime is by far not the optimal, but Ive left it that way to make the code easier to read. I need to return a median of only a certain category on a spread sheet. Example Below Airline 5 Auto 20 Auto 3 Bike 12 Airline 12 Airline 39. Excel Function Help File' title='Excel Function Help File' />The For block, which executes a part of the code a specified number of times. For example Public Function Factorialvalue As Integer As Long. Dim result As Long. Dim i As Integer. If value 0 Thenresult 1. Else. If value 1 Thenresult 1. Elseresult 1. For i 1 To valueresult result i. Next. End If. Factorial result. Excel Function Help File' title='Excel Function Help File' />End Function. Notice the elements again FOR variable lower limit TO upper limit code NEXT. Also notice the added Else. Os 2 Warp 4 here. If element in the If statement, which allows you to add more options to the code that is to be executed. Finally, notice the declaration of the function and the variable result as Long. The Long datatype allows values much larger than Integer. Shown below is the code for a function that converts small numbers into words.