// Inside your command already.

_listnode <Player> *parse = playerlist->head;   //set to first link of the player linked list

while (parse)   //parse will be NULL when we reach the last link
{
   Player *p = parse->item;   //item is the actual data stored in the link

   // do functionality here
   // Example 1: sendPrivate(p,"*watchdamage"); // turns on all pilot's watchdamage
   // Example 2: if (p->safety != 0) sendPrivate(p,"*spec"); // spec all pilots in safe zone
         sendPrivate(p, "*warpto %s %s", xcoord, ycoord);  // Might work?
   parse = parse->next;   //set parse to the next link
}

string xcoord;
string ycoord;
. . .
xcoord, ycoord = c->final.split(":");   // Completely guessing here.

// Inside your command already.

_listnode <Player> *parse = playerlist->head;

while (parse)
{
   Player *p = parse->item;

         sendPrivate(p, "*warpto "+(String)xcoord+" "+(String)ycoord);  // Will work if xcoord and ycoord are decleared as variables

   parse = parse->next;   
}

String xcoord, ycoord;

ycoord = c->final;
xcoord = ycoord.split(":");   // Leave the right part besides : in ycoord and put the part infront of : in xcoord