Here are a couple of EX4 De-Compilers I have found so far. I have not tried any of these as of yet so if you give them a go let me know how you get on with them. If you need something specifc decompiled email me at info@greattradingsystems.com and I might be able to help or rather might know a man who can.
Free or Free to Try
Decompiler EX4-TO-MQ4 4.0.215.6
“Recover your lost metaquote sources with this MetaTrader 4 ex4 decompiler. Easy install, easy use. Just run decompiler and drag-and-drop any ex4 file on decompiler window. You can edit and compile again your MQL code.”
“Recover your lost metaquote sources with this MetaTrader 4 ex4 decompiler. Easy install, easy use. Just double click on your ex4 file and it will be immediately decompiled and opened in MetaEditor, where you can edit your metaquote code”.
“Recover your lost metaquote sources with this MetaTrader 4 ex4 decompiler. Easy install, easy use. Just run decompiler and drag-and-drop any ex4 file on decompiler window. You can edit and compile again your MQL code. This version is the first release on CNET Download.com.”
Paid For Service
Ex4 To Mq4 Decompilier Service
“You have Ex4 file. But you lost Mq4 file! Don’t worry. We help you convert EX4 to MQ4. This is Ex4 to Mq4 decompilier service. The Mql files compilier again.And we guaranteed mql files can recompilier!”
Update
I came across this guy on a forum who is selling decompiling software for $20. Not sure if he has any ‘more’ to sell as he said he was only selling 5 but you never know. This was his email address.
andrix21@gmail.com
another decompiling service here with recommendation
http://www.greattradingsystems.com/2009/10/mt4-decompiling/