no, as long as it is only short-term jobs, you can keep your 2-year period with dagpenge. In fact by working you will be able to extend the period in the last end. 1 hour of work gives two more hours with dagpenge.
Off course you can not get dagpenge for the same period where you have this vikar-job. You must tell the A-kasse about the job on the monthly "dagpenge-kort", you fill out online at the A-kasse website. The A-kasse will then deduct the hours you have worked in your dagpenge-payment.
Because you will work 37 hours per week, you can not get supplementary benefits.
If you are not approved for supplerende dagpenge, then you can not receive dagpenge in weeks where you work.
I recommend that you also talk with your A-kasse about this.
Anders Weber, www.a-kasser.dk