Yes, several ways. But how comfortable are you with VBA?
Basically, I would build the button using a button wizard. An option exists for you to run SQL using this wizard. Let it build that code, but then you are going to go back in and edit the code it built for you. You might have to create a dummy update query that updates the right field for some dummy value, say, XYZ, in quotes, and your criteria string of NA must also be part of that query. Use the query grid (design view) to create the query. For TWO reasons, you would want this query to exist.
OK, now you have button event code to run a query. But... that code will reference the dummy query. Look up the action that it built for you, probably either RunSQL or Execute or something like that. The Help Files will tell you how to supply a STRING instead of a stored query.
Now before the DoCmd that runs your query, you have to do a few things.
First, using an InputBox, capture your required data.
Second, build a string containing the desired Update SQL information. Look at the dummy Update query in SQL view to see what this looks like. In this string, you will have an UPDATE verb and some field names and the WHERE clause that contains your criterion "WHERE field-name = ""NA"";"
OK, where it contains the constant "XYZ" in quotes, you will build the string
mysqlstring = "UPDATE table-name ..... " and put the field contents in via concatenation.
That should do it for you if you get the quotes right.
