Idea

Here's a script/command you can test that uses a percentage of the original length for the split point:

Object path=Model.find("AGVNetwork/Path1");   //param(1)
double splitPercent=50;                               //param(2)
Vec3 startLoc=path.getProperty("StartLocation");
Vec3 endLoc=path.getProperty("EndLocation");
Vec3 vec=endLoc-startLoc;
double magnitude=vec.magnitude;
double shortlen=magnitude*splitPercent/100;
Vec3 midLoc=startLoc+vec.normalized*magnitude*splitPercent/100;
treenode temp=nodeinsertinto(Model.find("Tools"));
Table.query("SELECT * FROM Objects() WHERE Object=$1",path).as(Table).cloneTo(temp);
Table(temp)[1]["StartLocation"]=midLoc;
Table(temp)[1]["Name"]+="_new";
Table.query("INSERT INTO Objects() (Class, Container, Name, StartLocation, EndLocation, PathClass, AGVOrientation, AccumulationType) SELECT Class, Container, Name, StartLocation, EndLocation, PathClass, AGVOrientation, AccumulationType FROM $1",temp);
temp.destroy();
Object newpath=path.up.last;
treenode points=getvarnode(path,"pathPoints");
treenode tcs=getvarnode(path,"transferClusters");
treenode newPoints=getvarnode(newpath,"pathPoints");
treenode newTCs=getvarnode(newpath,"transferClusters");
treenode point=points.last;
Object cp;
while (point && point.subnodes["distAlong"].value>shortlen){
    point.up=newPoints;
    point.subnodes["distAlong"].value-=shortlen; 
   //treenode tc=point.value.up.up;  
   // if (tc&&tc.up==tcs)   // do I need to move transfer clusters?
//tc.up=newTCs;
//cp=findownerobject(point.value);
//if (cp.getProperty("Class")=="AGV::ControlPoint")   // re-finalize control points?
//  function_s(cp,"finalizaSpatialChanges");
    point=points.last;
}
setvarnum(path,"length",shortlen);
path.setProperty("EndLocation",midLoc);
setcursor(3);
function_s(path, "refreshAllPathLinks", 0);
function_s(path, "refreshAllPathLinks", 0);  //twice
setcursor(1);

Alternatively you could specify a coordinate and change the code to project that onto the line at 90 degrees to find the intersection point.