Give this a try:
0010 ! begin
0020 x$="0000000001000000"
0030 print dec($00$+fn_atob$(x$))
0040 end
0100 FN_BTOA:! ^100
0110 ! Function which converts ASCII data to its binary representation
0120 def fn_btoa$(local x$)=hta(tbl(hta(tbl(hta(x$),"0123456789ABCDEF",
0120:$00010203101112132021222330313233$)),"0123",$00011011$))
0200 FN_ATOB:! ^100
0210 ! Function which returns ASCII value corresponding to a string a binary data
0220 def fn_atob$(local x$)=ath(tbl(ath(tbl(ath(x$),$00011011$,"0123")),
0220:$00010203101112132021222330313233$,"0123456789ABCDEF"))