It's not strictly indirect addressing but...
Call your SFC20 block.
For your SRCBLK put P#DB10.DBX0.0
Create a temp Int variable called Temp_Ret_Val and use #Temp_Ret_Val for your RET_VAL
For your destination put P#DB20.DBX0.0 BYTE 608
That should copy all the strings from DB10 into DB20
Adjust the SRC address, destination address and number of bytes depending on how many strings you want to move and where you want to move them to.