Very URGENT: Close Date and Modified Date to work depending on different sales stages

Hi All,
We have a requirement where we want Close Date and Modified Date to work depending on different sales stages.

i.e. Modified Date -> A, B, C

Here A, B & C are 3 initial sales stages.

Close Date -> D, E

Here D, E are Closed/Won & Closed / Lost respectively.

Note: Both Modified & Close Date are standard fields where system date timestamp displays automatically by default.

Appreciate your quick help please; can we apply some such workflow etc. in order to accomplish the same?

Thanks