The 28-year old former AFC Wimbledon forward arrives at the J Hearnden Skip Hire Community Stadium on an initial deal until January 1st.
Wales-born Roscrow began his senior career with Neat, before joining Llantwit Major in 2012 and Pontardawe Town in 2013.
His career took him to Cardiff Metropolitan University in the Welsh top flight in 2014 where he netted an impressive 34 goals in 79 league appearances, prompting then-League One side Wimbledon to bring him to south London in 2019, while also picking up a pair of caps for Wales C.