Here is an exec that may assist you with this effort.
It is using hardcoded IDs but could be changed to take variables for the input filename and output filename. It is just the guts with nothing fancy and does not deal with MDISKs. When this runs, any MDISKs defined in the current subconfig will get an error when you try to create the new subconfig based on the old one that was converted into a skeleton file.
The exec gets a current subconfig entry for an IDENTITY. In this case, YVOID-1 for IDENTITY YVOID. It creates a skeleton entry out ot it and then uses it to create the new subconfig entry. It then erases the interim files.
/* */
'VMSECURE GETENTRY YVOID-1'
PUSH 'FILE'
PUSH 'CHA YVOID-1 YVOID-2 * *'
PUSH 'TOP'
PUSH 'GET YVOID-1 DIRECT A'
PUSH 'TOP'
PUSH 'DEL'
PUSH 'BOT'
'VMSECURE ADMIN SKELETON YVOID-1 SUBCFG'
'VMSECURE ADDENTRY YVOID-2 YVOID-1 (IN YVOID ON TESTCP##'
'VMSECURE ADMIN SKELETON YVOID-1 (ERASE'
'ERASE YVOID-1 DIRECT A'
EXIT
In the line 'VMSECURE ADMIN SKELETON YVOID-1 SUBCFG', SUBCFG is a skeleton already created that has in it SUBCONFIG SUBF. This record is deleted before we GET the subcfg-name DIRECT on the 'A' disk that has the old subconfig info from GETENTRY.
This customer took some of our suggestions and wrote an exec of their own.
It had 4 steps:
1) to create a list of all subconfig id's
2) was to create the dasd from to label changes
3) was to edit all the subconfg files with new volser
And, the last step was to add into VMSECURE.
Then add the dasd in the dasd config file.