You can create GPO(Group Policy Objects) and link the GPO to domain or OU(Organization Unit) containing all the computers. Below are the steps to follow,

Step 1 : Creating a Security Group

First you need to create a security group called Local Admin
  • Log onto a Domain Controller, open Active Directory Users and Computers (dsa.msc)
  • Create a security Group name it Local Admin. From Menu Select Action | New | Group

  • Name the group as Local Admin.

  • Add the Help Desk members to Local Admin group. I will add two users say Tom and Bob.

Step 2: Create Group Policy.

Next you need to create a group policy called “Local Admin GPO”
  • Open Group Policy Management Console ( gpmc.msc )
  • Right click on Group Policy Objects and select  New. 

  • Type the name of the policy "Local Admin GPO"

Step 3: Configure the policy to add the “Local Admin” group as Administrators

Here you will add the Local Admin group to the Local Admin GPO policy and put them in the groups you wish them to use.
  • Right click “Local Admin GPO” Policy then select Edit.
  

  • Expand Computer configuration\Policies\Windows Settings\Security Settings\Restricted Groups
  • In the Left pane on Restricted Groups, Right Click and select “Add Group


  • In the Add Group dialog boxselect browse and type Local Admin and then clickCheck Names

  • Click OK twice to close the dialog box.

  • Click Add under “This group is a member of:”
  •  Add the “Administrators” Group.
  •  Add “Remote Desktop Users”
  •  Click OK twice


NOTE# When adding groups, you can add whatever you want, the GPO will match the group on the system, if you type “Admins” it will match a local group called Admins if it exists and put “Local Admin” in that group.

Step 4: Linking GPO

  • In Group policy management console, right click on the domain or the OU and select Link an Existing GPO

  • Select the Local Admin GPO

Step 5: Testing GPOs

Log on to a PC which is join to the domain and then run gpupdate /force and check the local administrators group. You should see Local Admin in that group now. Make sure all PCs you want to access should be move to an OU and properly link above GPO. Tom and Bob domain users can now access all PCs remotely as a local administrator.