Cách để dùng hàm excel trong access thì em xem trên diễn đàn và đã làm được nhưng để dùng những hàm đó trong Expression Builder thì em chưa làm được như hướng dẫn này. Mong các anh chị giúp đỡ
Creating Your User Defined Functions
Just as you would in Excel, simply enter your function into a standard module. In this example, I placed this small function called LastDayThisWeek into a standard Module. This particular function gives me the last day of the week.
If you have lots of User Defined Functions to keep track of, you can create one module to hold them all. For example, I typically put all my user defined functions into a module called My_User Defined_Functions. This makes finding and editing your functions easy.
In addition, when I activate the Expression Builder, I can drill into the My_User Defined_Functions module to see a complete list of my user defined functions.
Using Your User Defined Functions
In a query environment, you can use your User Defined functions in the same ways you would use built-in Access functions. In this example, I’m using my FirstDayLastMonth function.
In an Access Form, you can tie the Control Source for a text box to one of your User Defined functions (this same method works in Access reports).
In this example, this form will automatically execute the FirstDayLastMonth function each time it is opened to provide a value to the assigned text box.
And of course, your User Defined Functions can be used in other VBA procedures.
This procedure uses the FirstDayLastMonth function to find the first day of last month and then puts that date into a message box.
Đây là link gốc của hướng dẫn
http://datapigtechnologies.com/blog/inde...in-access/