UFS Additional space in extended partition

I am NOT trying to install FreeBSD in extended DOS type partition. I am running x86 laptop and my disk is partitioned in MBR type scheme. FreeBSD is all (root and swap) in primary partition. I have space in extended partition and I'd like to allocate part of it as additional slice. I'd like to place swap into it, if possible, and resize slice where root is to use all of the space in primary partition. Is that even possible ?

Please don't point me to "Disk Organization" because either the answer is not there or I can't find it. Thanks.
Do you really need the extended partition to be an extended EBR partition? If it's not going to be used for anything else but FreeBSD you can add a new slice (primary DOS partition) and divide that further into FreeBSD partitions.
I am to keep EBR partition. Slackware Linux on the same disk is using one logical partition, so I need it. I'd just like to know is it generally possible to put "non-root" slice into EBR partition.

I was also thinking about adding an ext2 (or ext3, ext4, whatever FreeBSD can support) into EBR and mount it permanently under FreeBSD root. Is there any reason not to keep ports on it ? Or perhaps some other FS with UNIX-like permissions and naming conventions which FreeBSD could mount ?
Here is what I have done. It is not any sort of general solution, but lot of people run FreeBSD and Linux in multi - boot, and they might find it useful. I created logical partition in Linux and formatted it as ext2fs. To have it mounted permanently in FreeBSD, you are going to need e2fsprogs port or package and you should add it to /etc/fstab. The idea is to provide shared partition for Linux and FreeBSD.

I also moved ports to new ext2fs. As far as I understand, it is not uncommon practice to keep ports on separate partition. Whichever FS is used, a number of inodes must be increased. That is achieved exactly the same as for UFS. Instead of 'newfs -i 1024' you run 'mkfs -i 1024'. I have built XDaliClock from ports as sort of test.

I am still curious about the idea of using ufs formatted logical partition in FreeBSD. I feel it should be possible. Disk utility which comes with bsdconfig will not do it. I am going to learn more about gpart.