Code:
public PlantABomb( player ) {
new iEntity = create_entity( "weapon_c4" );
if( !iEntity )
return;
DispatchKeyValue( iEntity, "detonatedelay", "50" );
DispatchSpawn( iEntity );
new Float:origin[ 3 ];
pev( player, pev_origin, origin );
engfunc( EngFunc_SetOrigin, iEntity, origin );
force_use( iEntity, iEntity ); // This plants it
}