You might be able to try getting the user onOpen. Then depending on the user, activate the appropriate cell.
This assumes all users are on the same domain and have access to the sheet. This won't work where a user has not granted permission.
Something like this (I don't know if this will work or not, and going from memory, so excuse any errors):
function onOpen() {
var user = getUser();
activateCell(user);
}
//From: Script services --> Base --> Session
function getUser() {
var user = Session.getActiveUser().getEmail();
return user;
}
function activateCell(user) {
var cell;
//maybe use a switch depending on how many users there are
switch (user) {
cell = "A1";
break;
cell = "E5"
}
var ss = SpreadsheetApp... etc etc //get the spreadsheet, get the sheet
ss.getRange(cell).activate;
}
This, or a similar approach is how I would attempt it. I hope that helps!