How to change vecs' postion towards another vec?

I use LineTraceByChannel, and wanna to change vector “Location” distance in some units with regard its start location!

Use a Lerp, using the Start as A and the end as B.

Then use the alpha to choose the distance.

This won’t correct for different distances. For big distance - big lerp, for small - very small. I need to change distance in units… it must be statically for all distances.