How to convert a potential into a lead

I am new to to zoho.

I would normally in (my mind) convert a potential, (this could be one in the future) for instance i called XYZ Company in January 2014, they told me they may be interested in buying from us in June - I would class this as a "future 'potential'", and record it as such, then i would call again in June, and if they are in the market to buy i would convert this to a lead.

I guess (without knowing the correct way to do this) how I would do this in Zoho is for the above particular senario, i would create an account and create the potential, then later convert to a lead in June.

How should I do this in zoho?