visual studio 2010 - How do I configure IISExpress for multiple web workspaces when using TFS with VS2013? -

some history...

for time i've been using vs2010 tfs developing web site work on using multiple workspaces; example, workspace dev1 might have code partially implemented new feature, i'll fire 2nd instance of vs2010 , open same solution in workspace dev2 fix bug.

within solution file, port number fixed if open 1 instance in workspace url testing starts http://localhost:8251/core/.... if opened 2nd copy, vs2010 detected first instance, checked out solution file , assigned random port number. hence url might start http://localhost:12345/core/.... obviously, port number unimportant of time, it's convenient have fixed testing.

all worked under vs2010 using 'internal' webserver (cassini). open multiple instances of vs2010 using solutions in difference workspaces , there never 'cross activation' opening page in 1 instance accessed files different workspace.

...end of history.

we're moving vs2013 , 'internal' webserver has been removed iisexpress has used testing. question how configure works multiple tfs workspaces port number may dynamically assigned.

the first thing noticed stored startup page "default.aspx?param=..." doesn't work right , iisexpress under vs2013 tries open http://localhost:8251/default.aspx... omitting project name. after initial failure, need enter new url. clearly, once migrate vs2013 vs2010, can change startup page "core/default.aspx..." , should well.

i've been told can configure file "iisexpress/applicationhost.config" in documents (?) folder include lines similar to...

 <site name="core" id="3">     <application path="/" applicationpool="clr4classicapppool">         <virtualdirectory path="/" physicalpath="c:\working\dev1\core" />     </application>     <application path="/core" applicationpool="clr4classicapppool">         <virtualdirectory path="/" physicalpath="c:\working\dev1\core" />     </application>     <bindings>         <binding protocol="http" bindinginformation="*:8251:localhost" />     </bindings> </site> 

this seems work first workspace, it's not clear how extend multiple workspaces, given port number dynamically assigned 2nd, 3rd, etc solutions. duplicating above dev2, dev3, etc, suffixing site name , changing id neeeded, seemed work initially, further investigation indicates iisexpress uses dev1 workspace! i.e. it's using first matching application. have name sites individually workspace? have hardcode port number each instance? how |i refer each one? seems me complete mess after simplicity of vs2010's handling of multiple workspaces!

in short, want able open 1 or more instances of vs2013 using multiple workspaces referencing same solution , able run multiple copies of application side-by-side, possibly using dynamically assigned port numbers, , know each instance using own folders. if there's 1 instance open, should use default port number, that's in use, should assigned random port, , not interfere other solution.

additionally, while testing, seems rewrites file. normal, since once have configuration works, don't want altered! [update: seems i'm not 1 concern others have asked here! however, there doesn't seem solution given works.]

it simpler if ms hadn't removed cassini... :sigh:

update: seems difficult in vs2012 other have similar problem!

have tried setting configuration file using command line parameter?