Reporting Services :: Pass Multiple Values From Field To Sub Report

I would like to know how does subreport accept multi value, and how should i modify my expression so that the sub report will display correctly.

My main report will pass dynamic number of account number to sub report, it depends on how many account number a person has. I have my sub report parameter Data Type set as "Allow multiple values" and the visibility is "Visible".

Currently, I am using the following expression to try to pass multi value from main report to sub report. I had tested the result of that expression. It is showing the following result when there are 3 account numbers to pass to sub report.

1534896
1563498
1593548

With that expression, when only one account no is pass from main report to sub report, the sub report will display the result. But when more than one account numbers are passing over, the sub report display nothing, it is blank.

--expression
=Join(LookupSet(Fields!PersonNo.Value,Fields!PersonNo.Value,Fields!AccountNo.Value,
"accounts"),""
+ VBCRLF)

*Note: I cannot put the account number into a multivalue parameter in the main report and pass from that parameter to sub report. I know this will workd BUT I had tried that by setting the default value in the multivalue parameter to the dataset that consists of the account number. That involves 100 thousand plus plus account numbers and it will for sure over the limit of 8000 characters.