Automatic shift schedule generator needed

Hello,

As a startup company its hard to purchase HR software. I am in need of shift schedule generator wich will provide me below options:

1. employee shift preference database
2. employee holiday registration

after this I would like to have a monthly schedule 1st March-31 March for example and generate automatically a schedule for 4 shifts (07h-15h,15h-23h,18h-02h,23h-07h) I will need 4 people in all shifts and there should be a shift inbetween for the personnel.

I have 26 employees.

Currently I am managing this by manual input but this makes it very hard. Would this be possible with VBA coding?