use as follows before [setup] archive names can be anything
Code:
#define Archives "{src}\Data1.arc;DestDir:{app};Disk:1"
#define Archives Archives + "|" + "{src}\Data2.arc;DestDir:{app}\xyz\xyz;Disk:1"
#define Archives Archives + "|" + "{src}\Data3.arc;DestDir:{app}\abc;Disk:2"
#define Archives Archives + "|" + "{src}\Data4.arc;DestDir:{app}\def;Disk:3"
will extract, and ask for the next disk.