Transfer Credit Memo to a G/L account

Hi, I would like to know can I transfer a credit memo to G/L account?

Customer sent us a debit note, then we issued a credit memo for it. We wanna transfer the amount to a G/L account (accrued expenses) instead of settlement. We have tried to transfer it in Cash receipt journal and Payment journal. like:

G/L Accrued Expenses -8,000

Customer ABC Co. 8,000 

However, it can not be posted in both side, the warning message is "Amount must be negative" under "Customer ABC Co. 8,000"

Thanks for the help.