Hello.
Using the Advanced options of the disk settings in Converter 4.3, you can add new disks and place the partitions on them accordingly.
With the result you have, the best bet is to:
Add two disks to the VM (one for D: and one for E:)
Take snapshot of VM
Stop the services and apps running in the VM
Assign the new drives drive letters and align them properly (if necessary)
xcopy the data from the D: drive to one of the new volumes
xcopy the data from the E: drive to the other new volume
re-assign drive letter to the the old D: drive
re-assign drive letter to the the old E: drive
rename the new volumes accordingly
Reboot and make sure everything works
Remove the original D: and E: drives from the C: partition
Use extpart to extend the C: drive
Good Luck!