In this article I will explain how you can create equations using VBA for word.

Step 1, Getting the Text String Associated with the Equation:

The first step for creating an equation in VBA for word is to determine the text string associated with that equation. You might not have noticed but equations in word are a basic text string. For example take a look at the the equation below:

If you copy the equation and paste it in a notepad this is what you get:

The text in the notepad might seem like nonsense, but the word editor understands this. In order to create equations in word using VBA, we too will have the create the text string above.

The text above can be converted back to a word equation by following the steps below:

Step 1: Copy the text in the notepad editor and paste it in an empty word document:

Step 2: Select the text in the word document and click on the “Insert Equation” button on the “Insert” tab

Step 3: Choose professional View:

Result:

As you can see the equation was created from the text string in the notepad file. So basically we need to be able to generate the text string in the notepad file to create the equation in word.

I will explain this in more detail in the following sections.

Step 2:

The next step for creating an equation is to move the cursor to the location you want to insert the equation.For more information about moving the cursor around the document please see the links below:

• Word VBA Using Bookmarks to Move the Cursor
• Word VBA, Move Cursor to Start of Document
• Word VBA, Move Cursor to End of Document
• Word VBA, Move Cursor to End of Line
• Word VBA, Move Cursor to Start of Line
• Word VBA, Go to Specific Line

Creating Simple Equations :

Equations can be made using the code below:

Sub Example1()
Dim objRange As Range
Set objRange = Selection.Range
objRange.Text = "y = x^2+1"
Call OMaths.Add(objRange)
End Sub


Note: If you want to keep reference to the newly created equation you could use the code below. You could then change the display to professional so it looks like a real equation:

Sub Example2()
Dim objRange As Range
Dim objOMath As OMath
Set objRange = Selection.Range
objRange.Text = "y = x^2+1"
Set objOMath = OMaths.Add(objRange).OMaths.Item(1)
objOMath.BuildUp
End Sub


Creating Complex Equations:

For more complex equations you can’t simply paste the text string in the VBA editor. For example lets say we want to create the equation explained at the start of the post. The first step would be to replace the text :

• “y = x^2+1”

with

• “f(x)=a_0+∑_(n=1)^∞▒(a_n  cos⁡〖nπx/L〗+b_n  sin⁡〖nπx/L〗 ) “

But this is what will happen if we try to make this replacement:

Sub Example1()
Dim objRange As Range
Set objRange = Selection.Range
objRange.Text = _
"f(x)=a_0+?_(n=1)^8n(a_n  cos??npx/L?+b_n  sin??npx/L? ) "
Call OMaths.Add(objRange)
End Sub


As you can see a lot of the characters are not recognized by the VBA editor and are replaced by a “?” character. The solution to this is explained in the steps below:

Step 1: Break the text string into different segments, separating the “?” characters:

"f(x)=a_0+" + ? + "_(n=1)^8n(a_n  cos"+ ?? + _
"npx/L" + ?+ "+b_n  sin' + ?? + "npx/L" +? +" ) "


For more information about concatenating strings please see the link below:

• VBA Excel String Processing and Manipulation

Step 2: Find the unicode value associated with the missing characters. The missing characters are:

• ∑
• 〖
• 〗
• ▒

I have written a program which returns the unicode value associated with characters. You can download the program at the link below and use it to find the unicode values associated with each of the characters above:

• VBA Get Characters Unicode Value

Step 3: Replace the “?” characters with the ChrW() function. The ChrW() function receives as input a unicode value and returns the character associated with it:

Sub Example3()
Dim objRange As Range
Dim objOMath As OMath
Set objRange = Selection.Range
objRange.Text = _
"f(x)=a_0+" + ChrW(8721) + "_(n=1)^8" + ChrW(9618) + _
"(a_n  cos" + ChrW(12310) + "npx/L" + ChrW(12311) + _
"+b_n  sin" + ChrW(12310) + "npx/L" + ChrW(12311) + " )"
Set objOMath = OMaths.Add(objRange).OMaths.Item(1)
objOMath.BuildUp
End Sub


Result:

You can download the file and code related to this article from the link below:

• Create Word Equation.docm

See also:

• Word VBA Equations Linear/Professional Display
• Microsoft (MSDN) OMath Object (Word)

If you need assistance with your code, or you are looking for a VBA programmer to hire feel free to contact me. Also please visit my website  www.software-solutions-online.com