how to replace a string in a cell with multi row character in matlab

i am using a template and regexprep to replace character. my template is huge so i can't post it here. so consider that my template name is templateGetC. I use

regexprep(templateGetC,'<final_bus_name>',component_name); 

to replace the 'final_bus_name' in my template with the component_name which has the value 'machine'. but what if i want to replace it with a multi row string. like if

a= ' start the experiment
    analyse the content
 end the experiment'

and if i want to replace 'final_bus_name' with 'a' it throws me an error that 'The third argument (REPLACE) must be a one-dimensional array of char or cell arrays of strings.'

is there any other way to replace it. i tried num2cell but it's horrible and just messes up the data.

i also tried strrep but it throws the error 'Input strings must have one row.'