To customise your personal ICL startup create a file of ICL commands and assign the environment variable AST_USER_ICL to that file, eg.
The most sensible place to add this definition is in your user shell startup file.csh> setenv AST_USER_ICL $HOME/mystuff.icl
Useful things to put in your ICL start-up are definitions of shell commands that you tend to use inside ICL, ICL procedures or command shortforms. An example is shown below,
{+ mystuff.icl - My personal ICL startup
{
{ Shortform for XRT source searching
{
defstring xrtpss pss psf="polar(xrt_pspc,0.02)" mask=varp
{
proc zoomsub outname
izoom
x1=0.0
x2=0.0
y1=0.0
y2=0.0
file=" "
icurrent suppress x1=(x1) x2=(x2) y1=(y1) y2=(y2) name=(file)
binsubset inp=(file) axes="1 2" axis1=((x1):(x2)) ~
axis2=((y1):(y2)) out=(outname) \
iwhole
endproc
This procedure allows the user to specify an area of the current
image using the cursor which is then subsetted using the BINSUBSET
application.