Registry multi string values

Does anybody know how to read REG_MULTI_SZ values from the registry ?
I used ReadRegStr for reading REG_SZ values but it doesent work with multiple string values.
I need this for reading from HKLM "SOFTWARE\Microsoft\Ras\Tapi Devices\Unimodem" "Address" and "Friendly name"
where if you have a modem attached to your computer it has the name of the modem and com values.

It doesn't work because NSIS doesn't support multiple strings in one buffer. You will have to create an extension DLL to do this for you, or use System.dll.