Oh, well you didn't say that you were using just Generals. I usually assume that members are using Zero Hour when they don't specify one way or the other.
http://www.cncgeneralsworld.com/forums/topic.asp?ARCHIVE=true&TOPIC_ID=8214 But it might be easier if you just add some command buttons to allow the players to build the workers/dozers. You can use the following actions:
[Scripting] Add a commandbutton to an object type.
[Map] Adjust the tech tree for a specific object type.
The script should look like this:
*** IF ***
True.
*** THEN ***
[???] Command button: 'Command_ConstructChinaDozer' is added to all objects of type 'AmericaCommandCenter' in slot number 2 (1-12).
[???] Command button: 'Command_ConstructGLAWorker' is added to all objects of type 'AmericaCommandCenter' in slot number 3 (1-12).
[???] Command button: 'Command_ConstructAmericaDozer' is added to all objects of type 'ChinaCommandCenter' in slot number 2 (1-12).
[???] Command button: 'Command_ConstructGLAWorker' is added to all objects of type 'ChinaCommandCenter' in slot number 3 (1-12).
[???] Command button: 'Command_ConstructAmericaDozer' is added to all objects of type 'GLACommandCenter' in slot number 2 (1-12).
[???] Command button: 'Command_ConstructChinaDozer' is added to all objects of type 'GLACommandCenter' in slot number 3 (1-12).
'AmericaVehicleDozer' becomes Buildable (Ignore_Prerequisites)
'ChinaVehicleDozer' becomes Buildable (Ignore_Prerequisites)
'GLAInfantryWorker' becomes Buildable (Ignore_Prerequisites)
When using the action to add command buttons, you should see a vertical charter, "
|", at the end of every command button name. Delete it, otherwise the action won't work. (This is a bug. 👎) If you don't see one, it's there none the less. Select the end of command button name, then press backspace. It should seem like nothing is deleted, but that character does get deleted. Once you've deleted the character, those 3 question marks will come up, just ignore them.
The action to ignore the prerequisites is necessary. If you don't include those actions & play the game, you won't be able to build the units. In the description window, you'll see that the unit requires that you own its corresponding command center. Ignoring the prerequisites allows you to build it anyway.