Hi,
If your writing code to run on multiple instances/different parameters then it is probably best to setup your parameters at the beginning of a file (or in separate file) and then reference the macro parameter throughout your code. Saves you have to cntrl+f replace each time. For example:
%let MYLIBNAME = ABC;
...
data &mylibname..newdataset;
set &mylibname..olddataset...
Then when you release to UAT you only need to change the one row %let.
As for find / replace, I don't think there are any other tools within the editor itself which would help. You could create a sas program to read in all the necessary sas files and doa datastep to replace the text with something else, but that sounds overcomplicated and takes time.