if it is possible to call a c-function from a Perl script.

Yes it is.

Say I have a VS C project I have created. Included in the VS project I have a function call createSocket(). This c-function when called, triggers a TCP/IP connection with my Perl module say ModuleA. In ModuleA, (that is Perl) can I call a doSomething() c-function that resides in my VS project that will inturn call createSocket().

You seem to be talking about both calling perl functions/methods from C and the reverse. Both are possible, and pretty well supported and documented, but it's a fairly advanced topic. You should read perlxstut, perlxs, perlembed and perlapi. Those are good resources and free (and probably the definitive word on the topic aside from reading the source to perl itself), but I recommend you get the extending and embedding perl book as an introduction to the topic. You'll still need the man pages, but the book will give you a good overview of what's possible, how to tackle the problems in general and just generally show you by example.