I have a folder with a thousands of files in it.
There is a subset of about 100 files which i need to work with consistently.
Is there a way to create some sort of virtual folder or view which only contains these files.
You could use Windows 7 Search to create a virtual sub-folder. For example, if you edit all the files within a moving-window of, perhaps, one month, then the following search (typed into the search box of the folder containing all the files) should work:
Alternatively, you could manually tag all the files you are interested in, and search based on the tag, e.g.:
Searches can then be saved as virtual folders, and will dynamically update if, for example, you add or remove files. This also saves you having to re-type the search query. Ars Technica have a more comprehensive guide to the search syntax here.
You can crate another folder and put 100 shortcuts to your 100 files in it.
Just select all the files by holding down the ctrl key and clicking the file, or shift if you want to select a long series of files. Then you can right-click-drag them into another folder and select "create shortcut here". Or you can of course do them one at a time.