I actually understand what you are trying to do, I briefly worked as a Leads Generator and I worked on a similar system, I will suggest you to build a back-office. I can do it, My bid is for a online back-office, with your current database stored online, secured, with complete access only to you, with different kind of users permissions and easy client management.
This is how I'll do it:
1. Import the current database (or part of it) on a webhosting, possibly cloud
2. Build a secure login page, I'll also manually ad a some sort of security layer (I'll explain)
3. If the Leads generator logins, he/she will be able to see the forms for generating new leads and if needed managing the old ones generated by him/her
4. If You login, you will see all the leads generated by every Leads Generator, you will be able to edit/update/delete every lead, client or agent.
-This back-office can be extended further, with more detailed client/agent/sells management or modules as emailing, pdf creation, file uploading (scanned documents, tickets)
If you like my idea, PM me