Attach the pic to the post like you are doing . And post a reply .

Your post will show , but the link for you pic will be right above the post .

Click on the attachment link and the pic will pop up .

Then right click and copy(or cut) the pic link in the top of that window .

Then come back and edit your original post . Click on image in the Instant UBB Code Window , and paste the link that you copied in the prompt window .