If you set the parameters in JC, Utilities, Maintain Job Cost Parameters to Port from General Journal, then AFTER you post the journal in General Ledger, Entries, Post to Journal a screen will come up that will ask you "Type of Job Cost Transaction?"  You can then select Charge, Adjustment, Billing, Credit Memo, Debit Memo, Cash Posting, Void Checks.  It will open you to that Job Cost Screen and you can post your transaction based on what you chose.