2
In wiwi, you've got a workaround with the [BLK ...] tag :
1 - step one : create a custom XOOPS block with the php code you need, and keep note somewhere of its block id once it's created (or remember the block title)
2 -step two : insert [BLK xxx] in your Wiwi page, at the place you want the block displayed (where xxx is either the block id or the block title).
3 - step three : save the page ; the block should now be displayed in the page ... doesn't it ?
Note : for now, no security check is done when displaying the block, so watch what you're doing
Xavier