Need Client Server Firewall Proxi Solution

Need solution to my (client server program) behind proxy and firewall. My problems is existing users are not able to? connect to server without configuring router and firewall.? I need a solution like? <[login to view URL]>? Their program works? behind firewall and proxy. My client server program is coded in VB6 (uses winsock)? So what? I need is? 1)? Analyze how team viewer works. 2) Anlyse my existing program. 3) Give me the best solution? for my problem. 4) And Code the solution in Vb6. ? Works with XP, Vista. Thanks BN