Making a non-CN dissolved gold solution ideal for electroplating
The problem is your amount of gold that you have. Normal chemical baths contain several grams per liter. So you will need to operate in small volumes. You can use this article - Chemical Papers
June 2012, Volume 66, Issue 6, pp 617-620
Date: 23 Dec 2011
Etching and recovery of gold from aluminum substrate in thiourea solution, that is using thiurea. Be aware of the low stability of this bath. The bath will degrade quite fast, but that is common problem of all non-cyanide gold baths. 

As the article deals with a gold dissolution, I would suggest to reduce the gold back to a solid state. Use the article or this Hydrometallurgy
Volume 55, Issue 2, March 2000, Pages 137–152, Gold electrowinning from aqueous–alcoholic thiourea solutions and then do the electrodeposition.