Changing the string is rather simple to do, check out this FAQ on the str_***** shortcode options that cMap enables. Here’s the link to the page that has all the str_***** shortcode options and much more for cMap.
Now, for the drop downs … yes, that is possible, but how really depends on the exact goals but in either case it would be rather complex and not simple to do if you’re new to PHP. Due to this complexity, it is not really something I can walk you thru either, sorry.
I hope this helps, even if a little.