Buttons cannot "hold" a value as they are just buttons, now you can put the text of a value into the caption of a button if thats what you mean... You can also display values from an array as the caption of buttons using VBA. But that's not storing anywhere, it's just display text.

Are you saying you want to be able to do like this?
DoCmd.OpenForm "CustomerF",,,"CustomerID=" & MyButton.Caption

Tag Property?

Alex is right - you can temporarily store data in its Tag property. Or you can set a different variable, like a Global Var or a Temp Var, when you click the button. But a Command Button itself has no value. Now a Toggle Button, on the other hand, can be bound to a field.