Use <cfset..> to assign variable from screen click/hover mouse event

I have rollover buttons: A  B C D E ..... Z and I want to assign a variable to the letter that is hovered or clicked by the mouse.

example <CFSET findchar = 'A%'> when user clicks or hovers over the "A"

Is is possible to read the text from the page on a mouse hover or click event and then use something like: <cfset findchar=(text on from mouse event)> to set the text to a string variable so that it can be used in a query like the one below?

<cfquery name="name" datasource="source">

SELECT * FROM Personnel

WHERE LastName like '#findchar#'

ORDER BY LastName ASC, FirstName ASC;

<cfquery>

Or does this require javascript?