finding a string and modifying content after the string in shell

I have a variable in shell

vpp_dpdk_dev_conf="dev='name=a,pci=2,mtu=1400,num-rx-queues=64,num-tx-queues=64,num-rx-desc=8,num-tx-desc=8,skip=false|true

Now I have another file where pci will be present, as a sample

pci 2 {
        num-rx-queues 30
        num-tx-queues 17
}

Now if my pci value present then I need to replace whatever is present with what is present is env variable as string and if not present add them.

Now this pci can have multiple instances but need to replace which matches pci x.

I am parsing the entire string and remove the "=" as in final file it won't be present.

function conf_file_update()
{
    for param in $@
        do
            name=${param%%=*}
            value=${param#*=}
            echo "value final" $value
            if [ "$name" == "pci" ]; then
               named_param="$name $value"
               VAR=$(grep -n "${named_param}" $CONF_FILE_PATH | cut -d : -f 1)
               VAR=$(($VAR+1))
               echo $VAR
                sed -i '$VAR,$s/^        '"${name}"' [0-9]*/        '"${name}"' '"${value}"'/' $CONF_FILE_PATH
            fi
    done
}
read ra DEV <<< $vpp_dpdk_dev_conf
for i in "${DEV[@]}"; do
    #if [[ -f $i ]] && [[ -w $i ]]; then
    for param in $(IFS='=';echo $i); do
        echo $i
        name=${param%% *}
        value=${param#* }
        if [ "$name" == "pci" ]; then
             conf_file_update $DEV
             exit 0

In the sed command I am trying to pass the line number from which it should start to replace but sed is not taking the $VAR and saying

> unknown command: `V'

Any Suggestion in the approach in the problem is highly appreciated.
Thanks
Niladri

Put $VAR, and all sed expression, between " (not ').
Change your line:

sed -i '$VAR,$s/^        '"${name}"' [0-9]*/        '"${name}"' '"${value}"'/' $CONF_FILE_PATH

with:

sed -i "$VAR,$s/^        ${name} [0-9]*/        ${name} ${value}/" "$CONF_FILE_PATH"