1) Welcome to the Party!
2) As you are obviously new here, I have some suggestions to help us all help you:
When you post, please post your entire configuration including (but not limited to) your installation method (7.X.X?) and vicidial version with build (VERSION: 2.X-XXXx ... BUILD: #####-####) which is NOT the SVN revision level (although listing that, too, is a good idea!).
This IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "manual/from scratch" you must post your operating system with version (and the .iso version from which you installed your original operating system) plus a link to the installation instructions you used. If your installation is "Hosted" list the site name of the host.
If this is a "Cloud" or "Virtual" server, please note the technology involved along with the version of that techology (ie: VMware Server Version 2.0.2). If it is not, merely stating the Motherboard model # and CPU would be helpful.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation | Intel DG35EC | Core2Quad Q6600
3) Configure your system so that agents in manual dial mode can call any of the three possible numbers on a lead. At that point when the agent matches a lead, they could then call the lead on any of the available numbers. If the agents are only able to dial the primary phone number, then when an agent matches a lead, that's all that will be available to dial.
4) If you are saying that you have already configured based on #3 for manual dial to alt_phone and address3, but this feature is disabled when matching a lead, that would be good information.
5) If you are saying that you have already configured based on #3 for manual dial to alt_phone and address3, but you want the number chosen to automatically match that previously provided number without having to Select alt_phone, that would also be good information. Not too much code to write, very doable.