Can an existing journal entry be copied and cut in half?

In JDE World, we have a process to open a posted journal, copy it into a new unposted entry, hit F6 for JE %, enter 50 into the Amt to Distribute, change the Action Code to 'C', and hit <Enter>. Each and every line of the long journal entry is cut in half.

Example - before:

1.1110 700.00

2.3580 800.00

2.6420 -1500.00

...(many many lines follow)

After:

1.1110 350.00

2.3580 400.00

2.6420 -750.00

...(many many lines follow exactly half of what they were above)

Is there an E1 version of this functionality? When clicking the Percent box after copying the existing entry then entering anything in the Amt to Distribute clears all existing amounts in the entry. Entering 50 in the % field in the grid also clears all amounts and takes 50% of whatever is in the Amt to Distribute field - not 50% of the original amount in the line.