The first step is to decide if you really want to become a programmer!
You might have an even harder time programming than the time you have right now beeing an admin. So ensure you want to start professional programming!
If you have choisen to become a programmer, you should pick your religion and focus on it. In other words: decide what you want to do; java, c++, .net, php, etc. You can't master them all, but you should pick one to start with.
Depending on your choise you can do a certification. If you pick Java you go for some Sun certs related to Java. If you pick .net you should do the microsoft certs, etc.
Those certs aren't that easy to get, but once you have them you will avoid a lot of questsions about you beeing able to code - while not having any professional experience neither a educational background matching a programmer.
Also you could try to focus on some development tasks in your given company and apply to new positions with that experience.
Last but not least, you could go for a trainee job - but this actually sucks ;)