How to switch career to a new platform?

hi
i am currently working on vb.net and PLM domain, in a support project. i wanted to work on c++, but unfortunately this is what i got in campus placement.

now i want to switch to a c++ job, after working for 1.5 yrs on vb.net.

all job ads i see.. need experience in that particular language. my question is, how can ome switch to a job in new platform if they want only those people who have already worked pn it?