Q: Is there any Digilent adapter connector to connect Digilent Vmod to FMC host boards?
No, Digilent does not offer any standard adapter connector to connect Digilent Vmod modules to FMC host/carrier boards.
One idea could be the self construction proposed in the Xilinx forum
VHDCI to FMC-LPC converter ... (http://forums.xilinx.com/t5/General-Technical-Discussion/VHDCI-to-FMC-LPC-converter-AD9739A-FMC-Card-Atlys-Spartan-6/m-p/234978)
Another (probably overkill) idea is to consider the Tews TFMC900 (http://www.tews.com/Products/ArticleGroup/TFMC/TFMC900.html). Double check connector genders and connector pin-outs.
The last idea is to find a suitable FMC module with a function similar to the Vmod / VHDC / VHDCI module to connect to the FMC host board.