Hey Bob,
Welcome to the forums!
As for script controllers.....although you can change your scripted controllers' scripts using maxscript.....it's a pretty tricky process.
You can directly access the script string of any script controller using the following syntax:
<script_controller>.script (returns string)
That being said....if you want to replace values within that string...the only way to do it would be to setup some tricky string operations.
In other words....you'd have to write a custom function that searches for specific text within that string and then replaces it without damaging the rest of the script.
If you've got hundreds of script controllers that all need to be changed, then yes...it would be worth putting the extra effort into writing a script that can do that....but if you've just got one or two I'd say don't waste your time
Hope that helps!