Parts needed for controlling vacuum line pressure with pressurized nitrogen

Question

I'm trying to assemble a simple setup where a line which is typically under vacuum can be pressurized by an external nitrogen supply, with this pressure regulated to less than 1 bar absolute (let's say 700 mbar). This nitrogen supply comes from the building and is at ~6 bar. What kind of regulator would let me do this? Would a conventional regulator which just reads gauge pressure work? As an additional note, there would not be any flow to or from a process occurring in this line while it is being pressurized or at the nominal 700 mbar regulated pressure.