How to substitute unsweetened coconut for sweetened coconut? I'm planning to make a coconut macaroon recipe that calls for:

1 cup of cream of coconut
2 tablespoons light corn syrup
4 egg whites
3 cups of unsweetened shredded coconut
3 cups of sweetened shredded coconut

plus small amounts of salt and vanilla (which are probably not relevant for this question.)
My local grocer was out of sweetened coconut, so I need to make the recipe with only unsweetened coconut instead.  What should I add to the unsweetened coconut to make it sufficiently sweet and moist?  How much?
The recipe, ironically, gives instructions on how to substitute sweetened coconut for the unsweetened (reduce cream of coconut to 1/2 c, omit corn syrup, add 2 Tbsp cake flour), but does not say how to go the other direction;  and the presence of the additional cake flour makes it difficult to reverse the directions.
Assuming you want to keep the recipe as close as possible to the original, you could simply replace the 3 cups of sweetened shredded coconut by sweetening yourself 3 cups of unsweetened shredded coconut.
Here, as an example, this is a recipe to sweeten 1 cup of unsweetened shredded coconut. You can find the details and adjust the recipe to make 3 cups. Keep in mind that it is designed for organic unsweetened shredded coconut, so the quality of your coconut should play an important role in the result. As a quick summary of the recipe they provide this image

PS: If you plan on storing some, remember to allow to dry as the recipe says.