I want to open iTunes with list of all the apps by a particular developer or company and in this very case my own applicaitons.
The problem is I don't know how should the URL string be
itms://itunes.com/apps/xxxx
what should I replace this xxx with ? and where would I find this text. Is it the company name? If so, should I look for it in developer account's profile info.
What else could be used? I heard there is some artistId or something like that. If so, how do I find it?
Well if you know the developer or company that you're looking for beforehand, you can use Apple's iTunes Link Maker web utility to generate links for the appstore (or any store really). You just put the developer's / company name in 'Search' field and set 'Media Type' to iOS Apps (or whatever you need). After the search is completed click on the appropriate result link under 'Artists' and you'll be presented with a sheet containing a link like this:
http://itunes.apple.com/us/artist/vasileios-akoinoglou/id339374807?uo=4
Note that you can safely replace http:// with itms:// so to avoid a redirection (if you use http then the link is first opened in Safari and then in Appstore).
As I can see from the link the components after artist is the developer / company name (whitespaces are replaced by dashes) and the id I think is the enrollment id (edit: it's not). I hope that this will be useful to you.