Hi Andy,
if you want create same cube of existing, you can. click on create info cube under respective info area,While creating you have options to copy from, there you can enter existing cube name(ZCUBE1). it will copy same structure of that cube(ZCUBE1) and you can use own technical name for copied one(ZCUBE2).
Info source: you may need to use old tx code - RSA1OLD. if your in BW 7.x you ca use RSA1.
Thanks