There are several AJAX interfaces in the Remote Download modular of BitComet, which can be used to access BitComet from Internet anywhere. (applied to v1.34 and later)
An example application is Transdroid (waiting for the latest version to support BitComet).
Following is the request path:
/panel/task_list_xml /panel/option_set?key=down_rate_max&value=123 /panel/option_set?key=up_rate_max&value=123 /panel/tasklist_action?id=start_all_download /panel/tasklist_action?id=start_all_seeding /panel/tasklist_action?id=stop_all /panel/tasklist_action?id=start_all_download /panel/tasklist_action?id=suspend_all
The returned data is in XML format.