Lua Code:
local f = CreateFrame("Button", nil, UIParent)
f:SetSize(32, 32)
f:SetPoint("CENTER")
f:SetNormalTexture("Interface/BUTTONS/UI-GroupLoot-Coin-Up.blp")
f:SetPushedTexture("Interface/BUTTONS/UI-GroupLoot-Coin-Down.blp")
f.Texture = f:CreateTexture(nil, "OVERLAY")
f.Texture:SetAlpha(0.9)
f.Texture:SetPoint("TOPLEFT", -3, 3)
f.Texture:SetPoint("BOTTOMRIGHT", -3, 3)
f.Texture:SetTexture("Interface/Minimap/MiniMap-TrackingBorder")
f.Texture:SetTexCoord(0.05, 0.54180000305167, 0.03, 0.5199999833107)
the SetTexCoord and SetPoints can be better adjusted if you want to go with the "full sized" overlay.