The Somfy R28 can be used to upgrade your manual shade, as long as it's the type that Somfy provides crowns and drives for. Additionally, the bracket on the manual control side needs to be a 2-part bracket.
If you let us know what the diameter of the shade's tube is and a photo of the bracket, We'll be able to tell for sure(send us an e-mail at firstname.lastname@example.org
An alternative option is to get the R28 blind kit. It includes the tube and all the necessary part, except for the fabric. This allows you to take the fabric of the old shade and use it on the new one. (The tube comes with an adhesive strip you can use to easily attach the fabric to)
Kits ship from stock and are delivered in 2 working days.