SQL 2012 :: SSIS And Variables With Where Clause

I have an SSIS package which uses variables and foreach loop containers so connect to multiple instances to retrieve config data. I am adding an extra step to include the port of each instance.

I used a select from a central table to get the connection strings, which is put into [User::Server2]

1) execute SQL task to collect the port

(DECLARE @portNumber NVARCHAR(10)
EXEC xp_instance_regread
@rootkey = 'HKEY_LOCAL_MACHINE',
@key =

'SoftwareMicrosoftMicrosoft SQL ServerMSSQLServerSuperSocketNetLibTcpIpAll',
@value_name = 'TcpPort',
@value = @portNumber OUTPUT
)

Which is then put into a variable @Portnumber

2) I then need to insert this into a certain server with a where clause including another variable

so something like
"INSERT INTO DBO.InstanceConfig VALUES ('"+@[User::Portnumber]+"') where Serverinstance = ('"+@[User::Server2]+"')

but it doesnt work like that.. is there an easier way