Thank you very much for the reply. I read the Metadata API but there isnt a clear example of create/update a custom object with its information like fullname, enable reports, so on and custom fields (that is what I need). Could any give me an example please? or maybe an url where is more explained the metadata API.
@RAVS: Lazy person! here you go, it caters to your requirement: https://developer.salesforce.com/docs/atlas.en-us.api_meta.meta/api_meta/customfield.htm
https://developer.salesforce.com/docs/atlas.en-us.api_meta.meta/api_meta/customfield.htm