I presume you mean this one - courtesy of Country Joe and the Fish at Woodstock

Feel Like I'm Fixin' To Die Rag

Come on all of you big strong men,
Uncle Sam needs your help again,
He's got himself in a terrible jam,
Way down yonder in Vietnam,
So put down your books and pick up a gun,
We're gonna have a whole lot of fun!

Chorus
And its l, 2, 3, What are we fighting for?
Don't ask me, I don't give a damn
Next stop is Vietnam,
And its 5, 6, 7, Open up them pearly gates,
There ain't no time to wonder why,
Whoopee! We're all gonna die!

Come on generals, let's move fast,
Your big chance has come at last,
Now you can go out and get those Reds,
The only good Commie is one that's dead,
You know that peace can only be won
When we've blown 'em all to kingdom come!

Come on Wall Street, don't be slow,
Why man this is war Au-go-go,
There's plenty good money to be made
Supplying the army with tools of the trade,
Just hope and pray if they drop the bomb
They drop it on the Viet Cong!

Come on mothers, throughout the land,
Pack your boys off to Vietnam,
Come on fathers, don't hesitate,
Send your sons off before its too late,
You can be the first one on your block,
To have your boy come home in a box.