hi ,According to my knowledge i think so you cannot work in visit visa,but you can arrive qatar with visit visa,and search for a job,and after you find a job your company will give you work visa.but you have to inform the company before you join that you need company visa.
may i know which nationality u are and are u female or male.because for philipins female qatar company have many visa.but if ur a indian female it is very difficuilt to get visa.