As per my understanding you need 5 different types of excel utility having different functionalities.
I would suggest the following for each case:-
1. Create a Google Form to collect necessary data from user input and save the data submitted through google form in a Google sheet. From the Google sheet you can sort, find etc. from the database.
2. Create a Google sheet with an auto increment column for Memo No.
3. This is also can easily achieved using google sheet.
4. Create google sheet with necessary columns e.g. employee name, DOB, DOJ, Designation, Scale of Pay, Increment, Nominations, leave etc.
5. Google sheet here also can be used to maintain cash book register.
I personally use google sheet to save lot of information so that i can easily access it through various devices online.