I need to add a custom calculated field to the Deals section.

Each Deal has an input date (Fecha entrada). 

After entering this date I need to compose a new field, called EntradaNumero as:

Fecha entrada = Day(Fecha entrada) & Month(Fecha entrada) & Year(Fecha entrada) & "/" & Count(Deals where Fecha entrada = given date)+1

That is, it has to compose the date as DayMonthYear, ad a slash (/) and count the deals entered for thre same date plus one, and assign this result to the field NumeroEntrada.

Of course, the day, month and year has to be 2 digits each one, adding a zero at left when needed, and also for the counter.

I'm working with the custom fields and custom functions, but I can't find how to do it, how to find the fuctions to count the records...

This is my second day with zohocrm Enterprise edtn.

Thanks in advance for your help