is there a possibility to convert fields of a Lead into a custom object besides Opportunities, Contacts and Accounts?
Furthermore is there a chance to see all custom fields in the field assignment of custom fields? For me there are always some missing at the moment or they are selectable in the wrong field.
Thanks in Advance!
As Jayant mentioned, there is no way to utilize the out-of-the box lead conversion functionality to work with custom objects.
While I've never used it, this app may help you out: Custom Object Lead Conversion.
Your other option would be to look into developing a custom lead convert process with Apex.
You may have some luck browsing the Developer Boards if interested.
I'm not sure I fully understand your second question re: seeing all custom fields in field assignment. Are you referring to the lead conversion field mapping? Could you elaborate?