I'm not sure about VHD's from acronis, but I have done the following with Vitrual Server VHD's successfully:
1. Copy VHD to NFS or EXT3 storage
2. Rename to UUID.vhd (pick a unique UUID, I usually just index up by 1 off of an existing one)
3. Run xe sr-scan uuid=sr-uuid (you can use xe sr-list name-label=sr-name
4. Set a Name Label using xe vdi-param-set uuid=disk-uuid name-label=disk-name
5. Attach the imported disk to a VM