import users from excel

Can you clarify a bit on "import list users"?  You haven't given us much to go on here.  I.E., what users are listed on the excel?  Is it a list of usernames that already represent valid usernames in the system?  XOR is it a list of people for whom there are no user accounts and they will need to be created?

What group(s) do they need to be added to?  Is it a static group or list of groups for all user(s) in question, or will those groups change depending on the user line-item?

Generally, you should be able to automate any such use cases by utilizing the "read excel sheet paging" functionality found in the Excel Tools plug-in, then parsing and looping over that data in a process.  But what exactly that process does will depend heavily on what your source data looks like exactly, and what you need to accomplish.