The exported hex values you have to put together sequentially for instance 00 3E F4 becomes 003EF4. Assign that to a variable and write to the registry like the code below.

 Code:
$hexvalue = "001122335543352545432542"
$=WriteValue('HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\0006\0', 'IsdnMultiSubscriberNumbers',$hexvalue,'REG_MULTI_SZ')