If you use mIRC v7.32, you can type the following to see the SSL status as well as the locations of the DLLs that mIRC is loading:
//echo $ssl | echo $sslready | echo $sslversion | echo $ssldll | echo $ssllibdll
If you are using the OpenSSL installer on Windows 7 64bit, the files will be installed in Windows\SysWOW64 which is where Windows 7 stores 32bit DLLs. If you look in that folder, do you see the files there? If they are there, mIRC should pick them up automatically, as it does on my system.
That said, it sounds like you were able to set up everything so that $sslready is true, which means mIRC has loaded the OpenSSL DLLs. If you are using mIRC v7.22 and OpenSSL 1.0.1c on your computer and they are working for you, I cannot think of a reason why they would not work on your friend's computer, other than a Windows or other configuration issue.