Let's take Athlon Talos 3-12x40 with Center X reticle. Here are the measurements of this reticle :
Find and select in reticle list 'DIY Reticle'
Enter to Edit mode
Delete all elements
Change reticle name and measurements units
Begin reticle creation
Select element typ 'Thick bar', enter measurements from Athlon document and select element position 'Below center'
You will see created element on reticle
Create the same new element with element position 'Above center'
Create the same new element with element position 'Left and right'
Result view of reticle element list
Configure scope magnifications settings
Get parameters from Athlon document
You almost ready
That's it!