Sorry, I misread your question. It's possible to import the history of trades
from Wealth-Lab's Accounts tool, but importing trades
into the Accounts tool is not supported.*
The idea behind this is to make Wealth-Lab create trades on the dates of existing trades. Consequently, you need the data for
all the actual symbols included in your file with historical trade, and date/time should match those in Wealth-Lab. (You can not, for example, use the historical data of a stock to evaluate performance of trading a futures contract.) Create a DataSet that matches your portfolio and load up enough data in the proper bar scale. Once this is completed, you can evaluate the performance of your real trades in performance visualizers.
P.S.
* Motivated traders may convert their own track record into Wealth-Lab's trade history file (called
TradeHistory.xml). Since this is a single-user task there is no turnkey solution available but you could build one for yourself using various classes found on 3rd party resources e.g.
Convert a CSV to XML using C#. Note: your usage is unsupported.