An adjustable mounting plate assembly comprising: a channel track for engagement with the surface of a desk, said channel track having a generally flat bottom surface, a hollow interior portion with a generally rectangular cross section defined by the flat bottom surface and two upper members extending from the flat bottom surface, and a slot extending the entire length of the channel track, said slot defined by the ends of the two upper members and allowing for communication into the hollow interior portion; at least two hubs, said hubs having a coupling with a bushing for receiving an office accessory; at least two plate nuts, said number of plate nuts corresponding to the number of hubs in the assembly, said plate nuts disposed in the hollow interior portion of the channel track, and wherein each hub is secured to a corresponding plate nut by a bolt which extends through the hub, through the slot in the channel track and into engagement with the corresponding plate nut, wherein when the plate nuts and connected hubs are loosely connected, the plate nuts and connected hubs are free to slide in the slot in the direction of the length of the channel track and when the plate nuts and connected hubs are tightly connected, the plate nuts and connected hubs are retained in their position in the slot without any sliding movement; wherein said channel track further comprises endcaps disposed on each end of the channel track to prevent the plate nuts from sliding out of the hollow interior portion of the channel track; and characterized in that, the channel track is provided with a through-hole in the flat bottom surface, said hole allowing a bolt to engage an additional plate nut disposed in the hollow interior portion thereby securing the channel track to the desk. a channel track for engagement with the surface of a desk, said channel track having a generally flat bottom surface, a hollow interior portion with a generally rectangular cross section defined by the flat bottom surface and two upper members extending from the flat bottom surface, and a slot extending the entire length of the channel track, said slot defined by the ends of the two upper members and allowing for communication into the hollow interior portion; at least two hubs, said hubs having a coupling with a bushing for receiving an office accessory; at least two plate nuts, said number of plate nuts corresponding to the number of hubs in the assembly, said plate nuts disposed in the hollow interior portion of the channel track, and wherein each hub is secured to a corresponding plate nut by a bolt which extends through the hub, through the slot in the channel track and into engagement with the corresponding plate nut, wherein when the plate nuts and connected hubs are loosely connected, the plate nuts and connected hubs are free to slide in the slot in the direction of the length of the channel track and when the plate nuts and connected hubs are tightly connected, the plate nuts and connected hubs are retained in their position in the slot without any sliding movement; wherein said channel track further comprises endcaps disposed on each end of the channel track to prevent the plate nuts from sliding out of the hollow interior portion of the channel track; and characterized in that, the channel track is provided with a through-hole in the flat bottom surface, said hole allowing a bolt to engage an additional plate nut disposed in the hollow interior portion thereby securing the channel track to the desk.