  We present measurements of the magnetic field-induced microwave complex
resistivity changes at 47 GHz in Tl$_2$Ba$_2$CaCu$_2$O$_{8+\delta}$ (TBCCO)
thin films, in the ranges 58 K$<T<T_{c}$ and 0$<\mu_{0}H<$0.8 T. The large
imaginary part $\Delta\rho_{2}(H)$ points to strong elastic response, but the
data are not easily reconciled with a rigid vortex model. We find that, over a
wide range of temperatures, all the pairs of curves $\Delta\rho_{1}(H)$ and
$\Delta\rho_{2}(H)$ can be collapsed on a pair of scaling curves
$\Delta\rho_{1}[H/H^{*}(T)]$, $\Delta\rho_{2}[H/H^{*}(T)]$, with the same
scaling field $H^{*}(T)$. We argue that $H^{*}(T)$ is related to the loss of
vortex rigidity due to a vortex transformation.
