You might want to register and check here:
http://codebase.mql4.com
There appear to be a lot of MQL4 experts there.
For you to pull this off, MQL4 must support one of these Windows communication interfaces:
DLL
DDE
ActiveX
My quick search of the above surfaced nothing, but that doesn't mean MQL4 cannot do these. You'll need to contact their tech support or the experts for a definitive answer to the above.