You should try to understand what you've written and why it behaves the way it does. Follow the loops and conditions yourself, in your head. It's not magic, it's just logic.
You could do something like this, though of course I've not tested it:
int j = 0;
foreach (clsConnection i in Connections)
{
if (i.InGame == 1)
{
InSim.Send_BTN_CreateButton(i.PlayerName + " ^2A", Flags.ButtonStyles.ISB_DARK, 4, 29, (byte)(125 + j * 3), 3, (byte)(190 + j), i.UniqueID, 2, false);
}
else if (i.InGame == 0)
{
InSim.Send_BTN_CreateButton(i.PlayerName + " ^1•", Flags.ButtonStyles.ISB_DARK, 4, 29, (byte)(125 + j * 3), 3, (byte)(190 + j), i.UniqueID, 2, false);
}
j++;
}
But without understanding the code you're writing, and why, you're not going to get very far.